diff --git a/src/build-remote/build-remote.cc b/src/build-remote/build-remote.cc
index 18eee830b9e0..baad3bc7317d 100644
--- a/src/build-remote/build-remote.cc
+++ b/src/build-remote/build-remote.cc
@@ -81,11 +81,11 @@ static int main_build_remote(int argc, char * * argv)
 
         /* It would be more appropriate to use $XDG_RUNTIME_DIR, since
            that gets cleared on reboot, but it wouldn't work on macOS. */
-        auto currentLoadName = "/current-load";
+        PathView currentLoadName = "current-load";
         if (auto localStore = store.dynamic_pointer_cast<LocalFSStore>())
-            currentLoad = std::string { localStore->stateDir } + currentLoadName;
+            currentLoad = localStore->stateDir / currentLoadName;
         else
-            currentLoad = settings.nixStateDir + currentLoadName;
+            currentLoad = settings.nixStateDir / currentLoadName.native();
 
         std::shared_ptr<Store> sshStore;
         AutoCloseFD bestSlotLock;
diff --git a/src/libcmd/common-eval-args.cc b/src/libcmd/common-eval-args.cc
index 155b43b700b2..071fecefd90d 100644
--- a/src/libcmd/common-eval-args.cc
+++ b/src/libcmd/common-eval-args.cc
@@ -192,7 +192,7 @@ Bindings * MixEvalArgs::getAutoArgs(EvalState & state)
     return res.finish();
 }
 
-SourcePath lookupFileArg(EvalState & state, std::string_view s, const Path * baseDir)
+SourcePath lookupFileArg(EvalState & state, PathView s, const Path * baseDir)
 {
     if (EvalSettings::isPseudoUrl(s)) {
         auto accessor = fetchers::downloadTarball(
diff --git a/src/libcmd/common-eval-args.hh b/src/libcmd/common-eval-args.hh
index 75cb19334fe8..11d081728df2 100644
--- a/src/libcmd/common-eval-args.hh
+++ b/src/libcmd/common-eval-args.hh
@@ -41,6 +41,6 @@ private:
 /**
  * @param baseDir Optional [base directory](https://nixos.org/manual/nix/unstable/glossary#gloss-base-directory)
  */
-SourcePath lookupFileArg(EvalState & state, std::string_view s, const Path * baseDir = nullptr);
+SourcePath lookupFileArg(EvalState & state, PathView s, const Path * baseDir = nullptr);
 
 }
diff --git a/src/libexpr/eval-settings.cc b/src/libexpr/eval-settings.cc
index 2ccbe327fad1..e7e92c1a2379 100644
--- a/src/libexpr/eval-settings.cc
+++ b/src/libexpr/eval-settings.cc
@@ -58,7 +58,7 @@ Strings EvalSettings::getDefaultNixPath()
             if (s.empty()) {
                 res.push_back(p);
             } else {
-                res.push_back(s + "=" + p);
+                res.push_back(s + "=" + p.native());
             }
         }
     };
diff --git a/src/libstore/globals.cc b/src/libstore/globals.cc
index dfe3044ea348..d4455a96f8de 100644
--- a/src/libstore/globals.cc
+++ b/src/libstore/globals.cc
@@ -84,7 +84,9 @@ Settings::Settings()
     }
 
 #if defined(__linux__) && defined(SANDBOX_SHELL)
-    sandboxPaths = tokenizeString<StringSet>("/bin/sh=" SANDBOX_SHELL);
+    sandboxPaths = std::set {
+        Path { "/bin/sh=" SANDBOX_SHELL }
+    };
 #endif
 
     /* chroot-like behavior from Apple's sandbox */
@@ -154,7 +156,7 @@ std::vector<Path> getUserConfigFiles()
     // Use the paths specified in NIX_USER_CONF_FILES if it has been defined
     auto nixConfFiles = getEnv("NIX_USER_CONF_FILES");
     if (nixConfFiles.has_value()) {
-        return tokenizeString<std::vector<std::string>>(nixConfFiles.value(), ":");
+        return tokenizeString<std::vector<Path>>(nixConfFiles.value(), ":");
     }
 
     // Use the paths specified by the XDG spec
diff --git a/src/libstore/globals.hh b/src/libstore/globals.hh
index 0c71a7515536..4b9d6a26e1ea 100644
--- a/src/libstore/globals.hh
+++ b/src/libstore/globals.hh
@@ -276,7 +276,7 @@ public:
         )"};
 
     Setting<std::string> builders{
-        this, "@" + nixConfDir + "/machines", "builders",
+        this, "@" + (nixConfDir / "machines").native(), "builders",
         R"(
           A semicolon- or newline-separated list of build machines.
 
diff --git a/src/libstore/http-binary-cache-store.cc b/src/libstore/http-binary-cache-store.cc
index 5da87e935db6..eebe6344fd46 100644
--- a/src/libstore/http-binary-cache-store.cc
+++ b/src/libstore/http-binary-cache-store.cc
@@ -26,7 +26,7 @@ class HttpBinaryCacheStore : public virtual HttpBinaryCacheStoreConfig, public v
 {
 private:
 
-    Path cacheUri;
+    std::string cacheUri;
 
     struct State
     {
@@ -40,7 +40,7 @@ class HttpBinaryCacheStore : public virtual HttpBinaryCacheStoreConfig, public v
 
     HttpBinaryCacheStore(
         const std::string & scheme,
-        const Path & _cacheUri,
+        const std::string & _cacheUri,
         const Params & params)
         : StoreConfig(params)
         , BinaryCacheStoreConfig(params)
diff --git a/src/libstore/local-binary-cache-store.cc b/src/libstore/local-binary-cache-store.cc
index 5481dd762e27..5e8684548034 100644
--- a/src/libstore/local-binary-cache-store.cc
+++ b/src/libstore/local-binary-cache-store.cc
@@ -45,7 +45,7 @@ class LocalBinaryCacheStore : public virtual LocalBinaryCacheStoreConfig, public
 
     std::string getUri() override
     {
-        return "file://" + binaryCacheDir;
+        return "file://" + binaryCacheDir.native();
     }
 
     static std::set<std::string> uriSchemes();
diff --git a/src/libstore/local-fs-store.hh b/src/libstore/local-fs-store.hh
index 8fb08120012d..2ce59618bea6 100644
--- a/src/libstore/local-fs-store.hh
+++ b/src/libstore/local-fs-store.hh
@@ -16,17 +16,17 @@ struct LocalFSStoreConfig : virtual StoreConfig
         "Directory prefixed to all other paths."};
 
     const PathSetting stateDir{this,
-        rootDir.get() ? *rootDir.get() + "/nix/var/nix" : settings.nixStateDir,
+        rootDir.get() ? *rootDir.get() / "nix/var/nix" : settings.nixStateDir,
         "state",
         "Directory where Nix will store state."};
 
     const PathSetting logDir{this,
-        rootDir.get() ? *rootDir.get() + "/nix/var/log/nix" : settings.nixLogDir,
+        rootDir.get() ? *rootDir.get() / "nix/var/log/nix" : settings.nixLogDir,
         "log",
         "directory where Nix will store log files."};
 
     const PathSetting realStoreDir{this,
-        rootDir.get() ? *rootDir.get() + "/nix/store" : storeDir, "real",
+        rootDir.get() ? *rootDir.get() / "nix/store" : storeDir, "real",
         "Physical path of the Nix store."};
 };
 
@@ -66,7 +66,7 @@ public:
     Path toRealPath(const Path & storePath) override
     {
         assert(isInStore(storePath));
-        return getRealStoreDir() + "/" + std::string(storePath, storeDir.size() + 1);
+        return getRealStoreDir() / Path::string_type { storePath, storeDir.native().size() + 1 };
     }
 
     std::optional<std::string> getBuildLogExact(const StorePath & path) override;
diff --git a/src/libstore/nar-accessor.cc b/src/libstore/nar-accessor.cc
index cecf8148f455..b8e061a8f6d6 100644
--- a/src/libstore/nar-accessor.cc
+++ b/src/libstore/nar-accessor.cc
@@ -15,7 +15,9 @@ struct NarMember
 
     std::string target;
 
-    /* If this is a directory, all the children of the directory. */
+    /**
+     * If this is a directory, all the children of the directory.
+     */
     std::map<std::string, NarMember> children;
 };
 
diff --git a/src/libstore/nar-info-disk-cache.cc b/src/libstore/nar-info-disk-cache.cc
index 07beb8acb0b3..3d6c11f383dd 100644
--- a/src/libstore/nar-info-disk-cache.cc
+++ b/src/libstore/nar-info-disk-cache.cc
@@ -208,7 +208,10 @@ class NarInfoDiskCacheImpl : public NarInfoDiskCache
             };
 
             {
-                auto r(state->insertCache.use()(uri)(time(0))(storeDir)(wantMassQuery)(priority));
+                auto r {
+                    state->insertCache.use()
+                        (uri)(time(0))(storeDir.native())(wantMassQuery)(priority)
+                };
                 if (!r.next()) { abort(); }
                 ret.id = (int) r.getInt(0);
             }
diff --git a/src/libstore/pathlocks.hh b/src/libstore/pathlocks.hh
index 42a84a1a37bb..09ad123bf30a 100644
--- a/src/libstore/pathlocks.hh
+++ b/src/libstore/pathlocks.hh
@@ -2,6 +2,7 @@
 ///@file
 
 #include "file-descriptor.hh"
+#include "file-path.hh"
 
 namespace nix {
 
diff --git a/src/libstore/profiles.cc b/src/libstore/profiles.cc
index 73d3976f43ae..17579d892dc3 100644
--- a/src/libstore/profiles.cc
+++ b/src/libstore/profiles.cc
@@ -39,7 +39,7 @@ std::pair<Generations, std::optional<GenerationNumber>> findGenerations(Path pro
 
     for (auto & i : readDirectory(profileDir)) {
         if (auto n = parseName(profileName, i.name)) {
-            auto path = profileDir + "/" + i.name;
+            auto path = profileDir / i.name;
             gens.push_back({
                 .number = *n,
                 .path = path,
@@ -255,7 +255,7 @@ time_t parseOlderThanTimeSpec(std::string_view timeSpec)
 void switchLink(Path link, Path target)
 {
     /* Hacky. */
-    if (dirOf(target) == dirOf(link)) target = baseNameOf(target);
+    if (dirOf(target) == dirOf(link)) target = baseNameOf(target).native();
 
     replaceSymlink(target, link);
 }
@@ -310,28 +310,30 @@ Path profilesDir()
     auto profileRoot =
         isRootUser()
         ? rootProfilesDir()
-        : createNixStateDir() + "/profiles";
+        : createNixStateDir() / "profiles";
     createDirs(profileRoot);
     return profileRoot;
 }
 
 Path rootProfilesDir()
 {
-    return settings.nixStateDir + "/profiles/per-user/root";
+    return settings.nixStateDir / "profiles/per-user/root";
 }
 
 
 Path getDefaultProfile()
 {
-    Path profileLink = settings.useXDGBaseDirectories ? createNixStateDir() + "/profile" : getHome() + "/.nix-profile";
+    Path profileLink = settings.useXDGBaseDirectories
+        ? createNixStateDir() / "profile"
+        : getHome() / ".nix-profile";
     try {
-        auto profile = profilesDir() + "/profile";
+        auto profile = profilesDir() / "profile";
         if (!pathExists(profileLink)) {
             replaceSymlink(profile, profileLink);
         }
         // Backwards compatibiliy measure: Make root's profile available as
         // `.../default` as it's what NixOS and most of the init scripts expect
-        Path globalProfileLink = settings.nixStateDir + "/profiles/default";
+        Path globalProfileLink = settings.nixStateDir / "profiles/default";
         if (isRootUser() && !pathExists(globalProfileLink)) {
             replaceSymlink(profile, globalProfileLink);
         }
@@ -343,12 +345,12 @@ Path getDefaultProfile()
 
 Path defaultChannelsDir()
 {
-    return profilesDir() + "/channels";
+    return profilesDir() / "channels";
 }
 
 Path rootChannelsDir()
 {
-    return rootProfilesDir() + "/channels";
+    return rootProfilesDir() / "channels";
 }
 
 }
diff --git a/src/libstore/sqlite.cc b/src/libstore/sqlite.cc
index 3175c197870a..d281d481cc97 100644
--- a/src/libstore/sqlite.cc
+++ b/src/libstore/sqlite.cc
@@ -62,7 +62,7 @@ SQLite::SQLite(const Path & path, SQLiteOpenMode mode)
     bool immutable = mode == SQLiteOpenMode::Immutable;
     int flags = immutable ? SQLITE_OPEN_READONLY : SQLITE_OPEN_READWRITE;
     if (mode == SQLiteOpenMode::Normal) flags |= SQLITE_OPEN_CREATE;
-    auto uri = "file:" + percentEncode(path) + "?immutable=" + (immutable ? "1" : "0");
+    auto uri = "file:" + percentEncode(path.native()) + "?immutable=" + (immutable ? "1" : "0");
     int ret = sqlite3_open_v2(uri.c_str(), &db, SQLITE_OPEN_URI | flags, vfs);
     if (ret != SQLITE_OK) {
         const char * err = sqlite3_errstr(ret);
diff --git a/src/libstore/sqlite.hh b/src/libstore/sqlite.hh
index 003e4d1013dc..a9a0055ecf23 100644
--- a/src/libstore/sqlite.hh
+++ b/src/libstore/sqlite.hh
@@ -5,6 +5,7 @@
 #include <string>
 
 #include "error.hh"
+#include "file-path.hh"
 
 struct sqlite3;
 struct sqlite3_stmt;
diff --git a/src/libstore/ssh.cc b/src/libstore/ssh.cc
index 04f45827943c..e634841ff354 100644
--- a/src/libstore/ssh.cc
+++ b/src/libstore/ssh.cc
@@ -35,7 +35,7 @@ void SSHMaster::addCommonSSHOpts(Strings & args)
         auto p = host.rfind("@");
         std::string thost = p != std::string::npos ? std::string(host, p + 1) : host;
         writeFile(fileName, thost + " " + base64Decode(sshPublicHostKey) + "\n");
-        args.insert(args.end(), {"-oUserKnownHostsFile=" + fileName});
+        args.insert(args.end(), {"-oUserKnownHostsFile=" + fileName.native()});
     }
     if (compress)
         args.push_back("-C");
diff --git a/src/libstore/store-api.hh b/src/libstore/store-api.hh
index ae8c224374fa..8d2e2c5e61c5 100644
--- a/src/libstore/store-api.hh
+++ b/src/libstore/store-api.hh
@@ -224,13 +224,13 @@ public:
     /**
      * Follow symlinks until we end up with a path in the Nix store.
      */
-    Path followLinksToStore(std::string_view path) const;
+    Path followLinksToStore(PathView path) const;
 
     /**
      * Same as followLinksToStore(), but apply toStorePath() to the
      * result.
      */
-    StorePath followLinksToStorePath(std::string_view path) const;
+    StorePath followLinksToStorePath(PathView path) const;
 
     /**
      * Check whether a path is valid.
diff --git a/src/libstore/store-dir-config.hh b/src/libstore/store-dir-config.hh
index 643f8854dd03..d2b63c57bdf5 100644
--- a/src/libstore/store-dir-config.hh
+++ b/src/libstore/store-dir-config.hh
@@ -67,7 +67,7 @@ struct StoreDirConfig : public Config
      * @return true if ‘path’ is a store path, i.e. a direct child of the
      * Nix store.
      */
-    bool isStorePath(std::string_view path) const;
+    bool isStorePath(PathView path) const;
 
     /**
      * Split a path like /nix/store/<hash>-<name>/<bla> into
diff --git a/src/libstore/uds-remote-store.cc b/src/libstore/uds-remote-store.cc
index 649644146bf0..e8da5af38d14 100644
--- a/src/libstore/uds-remote-store.cc
+++ b/src/libstore/uds-remote-store.cc
@@ -52,7 +52,7 @@ UDSRemoteStore::UDSRemoteStore(
 std::string UDSRemoteStore::getUri()
 {
     if (path) {
-        return std::string("unix://") + *path;
+        return std::string { "unix://" } + path->native();
     } else {
         return "daemon";
     }
diff --git a/src/libstore/uds-remote-store.hh b/src/libstore/uds-remote-store.hh
index 8bce8994a3a4..988a6404ad94 100644
--- a/src/libstore/uds-remote-store.hh
+++ b/src/libstore/uds-remote-store.hh
@@ -60,7 +60,7 @@ private:
     };
 
     ref<RemoteStore::Connection> openConnection() override;
-    std::optional<std::string> path;
+    std::optional<Path> path;
 };
 
 }
diff --git a/src/libstore/unix/lock.cc b/src/libstore/unix/lock.cc
index 023c74e349bf..bc1881d87a00 100644
--- a/src/libstore/unix/lock.cc
+++ b/src/libstore/unix/lock.cc
@@ -50,7 +50,7 @@ struct SimpleUserLock : UserLock
     static std::unique_ptr<UserLock> acquire()
     {
         assert(settings.buildUsersGroup != "");
-        createDirs(settings.nixStateDir + "/userpool");
+        createDirs(settings.nixStateDir / "userpool");
 
         /* Get the members of the build-users-group. */
         struct group * gr = getgrnam(settings.buildUsersGroup.get().c_str());
@@ -139,14 +139,14 @@ struct AutoUserLock : UserLock
         assert((uint64_t) settings.startId + (uint64_t) settings.uidCount <= std::numeric_limits<uid_t>::max());
         assert(nrIds <= maxIdsPerBuild);
 
-        createDirs(settings.nixStateDir + "/userpool2");
+        createDirs(settings.nixStateDir / "userpool2");
 
         size_t nrSlots = settings.uidCount / maxIdsPerBuild;
 
         for (size_t i = 0; i < nrSlots; i++) {
             debug("trying user slot '%d'", i);
 
-            createDirs(settings.nixStateDir + "/userpool2");
+            createDirs(settings.nixStateDir / "userpool2");
 
             auto fnUserLock = fmt("%s/userpool2/slot-%d", settings.nixStateDir, i);
 
diff --git a/src/libutil/archive.cc b/src/libutil/archive.cc
index 04f777d00f1e..d007a8607eb0 100644
--- a/src/libutil/archive.cc
+++ b/src/libutil/archive.cc
@@ -30,7 +30,7 @@ static ArchiveSettings archiveSettings;
 
 static GlobalConfig::Register rArchiveSettings(&archiveSettings);
 
-PathFilter defaultPathFilter = [](const Path &) { return true; };
+PathFilter defaultPathFilter = [](PathView) { return true; };
 
 
 void SourceAccessor::dumpPath(
@@ -97,7 +97,7 @@ void SourceAccessor::dumpPath(
         }
 
         else if (st.type == tSymlink)
-            sink << "type" << "symlink" << "target" << readLink(path);
+            sink << "type" << "symlink" << "target" << readLink(path).string();
 
         else throw Error("file '%s' has an unsupported type", path);
 
diff --git a/src/libutil/archive.hh b/src/libutil/archive.hh
index 28c63bb85506..c4ff8a866ca5 100644
--- a/src/libutil/archive.hh
+++ b/src/libutil/archive.hh
@@ -8,7 +8,6 @@
 
 namespace nix {
 
-
 /**
  * dumpPath creates a Nix archive of the specified path.
  *
diff --git a/src/libutil/args.hh b/src/libutil/args.hh
index 7759b74a93cc..89a5a61bbdcf 100644
--- a/src/libutil/args.hh
+++ b/src/libutil/args.hh
@@ -113,6 +113,11 @@ protected:
             , arity(1)
         { }
 
+        Handler(Path * dest)
+            : fun([=](std::vector<std::string> ss) { *dest = ss[0]; })
+            , arity(1)
+        { }
+
         template<class T>
         Handler(T * dest, const T & val)
             : fun([dest, val](std::vector<std::string> ss) { *dest = val; })
@@ -283,6 +288,18 @@ public:
         });
     }
 
+    /**
+     * Expect a path argument.
+     */
+    void expectArg(const std::string & label, Path * dest, bool optional = false)
+    {
+        expectArgs({
+            .label = label,
+            .optional = optional,
+            .handler = {dest}
+        });
+    }
+
     /**
      * Expect 0 or more arguments.
      */
diff --git a/src/libutil/config-impl.hh b/src/libutil/config-impl.hh
index 1da0cb6389ed..3ab645694f58 100644
--- a/src/libutil/config-impl.hh
+++ b/src/libutil/config-impl.hh
@@ -28,6 +28,14 @@ template<> struct BaseSetting<StringMap>::trait
 {
     static constexpr bool appendable = true;
 };
+template<> struct BaseSetting<Paths>::trait
+{
+    static constexpr bool appendable = true;
+};
+template<> struct BaseSetting<PathSet>::trait
+{
+    static constexpr bool appendable = true;
+};
 template<> struct BaseSetting<std::set<ExperimentalFeature>>::trait
 {
     static constexpr bool appendable = true;
@@ -48,6 +56,8 @@ bool BaseSetting<T>::isAppendable()
 template<> void BaseSetting<Strings>::appendOrSet(Strings newValue, bool append);
 template<> void BaseSetting<StringSet>::appendOrSet(StringSet newValue, bool append);
 template<> void BaseSetting<StringMap>::appendOrSet(StringMap newValue, bool append);
+template<> void BaseSetting<Paths>::appendOrSet(Paths newValue, bool append);
+template<> void BaseSetting<PathSet>::appendOrSet(PathSet newValue, bool append);
 template<> void BaseSetting<std::set<ExperimentalFeature>>::appendOrSet(std::set<ExperimentalFeature> newValue, bool append);
 
 template<typename T>
@@ -109,6 +119,10 @@ DECLARE_CONFIG_SERIALISER(bool)
 DECLARE_CONFIG_SERIALISER(Strings)
 DECLARE_CONFIG_SERIALISER(StringSet)
 DECLARE_CONFIG_SERIALISER(StringMap)
+DECLARE_CONFIG_SERIALISER(Path)
+DECLARE_CONFIG_SERIALISER(std::optional<Path>)
+DECLARE_CONFIG_SERIALISER(Paths)
+DECLARE_CONFIG_SERIALISER(PathSet)
 DECLARE_CONFIG_SERIALISER(std::set<ExperimentalFeature>)
 
 template<typename T>
diff --git a/src/libutil/config.hh b/src/libutil/config.hh
index 07322b60d7a0..76b40887adc5 100644
--- a/src/libutil/config.hh
+++ b/src/libutil/config.hh
@@ -8,6 +8,7 @@
 #include <nlohmann/json_fwd.hpp>
 
 #include "types.hh"
+#include "file-path.hh"
 #include "experimental-features.hh"
 
 namespace nix {
@@ -350,7 +351,7 @@ public:
 
     Path parse(const std::string & str) const override;
 
-    Path operator +(const char * p) const { return value + p; }
+    Path operator /(PathView p) const { return value / p.native(); }
 
     void operator =(const Path & v) { this->assign(v); }
 };
diff --git a/src/libutil/current-process.hh b/src/libutil/current-process.hh
index a5adb70cfd5b..a8423095e4b6 100644
--- a/src/libutil/current-process.hh
+++ b/src/libutil/current-process.hh
@@ -7,7 +7,7 @@
 # include <sys/resource.h>
 #endif
 
-#include "types.hh"
+#include "file-path.hh"
 
 namespace nix {
 
diff --git a/src/libutil/file-path.hh b/src/libutil/file-path.hh
index 6fb1001250b2..5c614596467a 100644
--- a/src/libutil/file-path.hh
+++ b/src/libutil/file-path.hh
@@ -10,43 +10,41 @@ namespace nix {
 
 /**
  * Paths are just `std::filesystem::path`s.
- *
- * @todo drop `NG` suffix and replace the ones in `types.hh`.
  */
-typedef std::filesystem::path PathNG;
-typedef std::list<Path> PathsNG;
-typedef std::set<Path> PathSetNG;
+typedef std::filesystem::path Path;
+typedef std::list<Path> Paths;
+typedef std::set<Path> PathSet;
 
 /**
  * Stop gap until `std::filesystem::path_view` from P1030R6 exists in a
  * future C++ standard.
  *
- * @todo drop `NG` suffix and replace the one in `types.hh`.
+ * @todo drop `` suffix and replace the one in `types.hh`.
  */
-struct PathViewNG : std::basic_string_view<PathNG::value_type>
+struct PathView : std::basic_string_view<Path::value_type>
 {
-    using string_view = std::basic_string_view<PathNG::value_type>;
+    using string_view = std::basic_string_view<Path::value_type>;
 
     using string_view::string_view;
 
-    PathViewNG(const PathNG & path)
-        : std::basic_string_view<PathNG::value_type>(path.native())
+    PathView(const Path & path)
+        : std::basic_string_view<Path::value_type>(path.native())
     { }
 
-    PathViewNG(const PathNG::string_type & path)
-        : std::basic_string_view<PathNG::value_type>(path)
+    PathView(const Path::string_type & path)
+        : std::basic_string_view<Path::value_type>(path)
     { }
 
     const string_view & native() const { return *this; }
     string_view & native() { return *this; }
 };
 
-std::string os_string_to_string(PathViewNG::string_view path);
+std::string os_string_to_string(PathView::string_view path);
 
-PathNG::string_type string_to_os_string(std::string_view s);
+Path::string_type string_to_os_string(std::string_view s);
 
-std::optional<PathNG> maybePathNG(PathView path);
+std::optional<Path> maybePath(PathView path);
 
-PathNG pathNG(PathView path);
+Path path(PathView path);
 
 }
diff --git a/src/libutil/file-system.cc b/src/libutil/file-system.cc
index b03bb767b6f1..95a8b008bc52 100644
--- a/src/libutil/file-system.cc
+++ b/src/libutil/file-system.cc
@@ -59,13 +59,12 @@ Path absPath(PathView path, std::optional<PathView> dir, bool resolveSymlinks)
             if (!getcwd(buf, sizeof(buf)))
 #endif
                 throw SysError("cannot get cwd");
-            scratch = concatStrings(buf, "/", path);
+            scratch = Path { buf } / path;
 #ifdef __GNU__
             free(buf);
 #endif
         } else
-            scratch = concatStrings(*dir, "/", path);
-        path = scratch;
+            scratch = Path { Path::string_type { *dir } } / path;
     }
     return canonPath(path, resolveSymlinks);
 }
@@ -120,14 +119,14 @@ Path canonPath(PathView path, bool resolveSymlinks)
 
 Path dirOf(const PathView path)
 {
-    Path::size_type pos = path.rfind('/');
+    PathView::size_type pos = path.rfind('/');
     if (pos == path.npos)
         return ".";
-    return pos == 0 ? "/" : Path(path, 0, pos);
+    return pos == 0 ? "/" : Path { path.substr(0,pos) };
 }
 
 
-std::string_view baseNameOf(std::string_view path)
+PathView baseNameOf(PathView path)
 {
     if (path.empty())
         return "";
@@ -142,11 +141,11 @@ std::string_view baseNameOf(std::string_view path)
     else
         pos += 1;
 
-    return path.substr(pos, last - pos + 1);
+    return PathView { path.substr(pos, last - pos + 1) };
 }
 
 
-bool isInDir(std::string_view path, std::string_view dir)
+bool isInDir(PathView path, PathView dir)
 {
     return path.substr(0, 1) == "/"
         && path.substr(0, dir.size()) == dir
@@ -155,7 +154,7 @@ bool isInDir(std::string_view path, std::string_view dir)
 }
 
 
-bool isDirOrInDir(std::string_view path, std::string_view dir)
+bool isDirOrInDir(PathView path, PathView dir)
 {
     return path == dir || isInDir(path, dir);
 }
@@ -314,7 +313,7 @@ void readFile(const Path & path, Sink & sink)
 }
 
 
-void writeFile(const Path & path, std::string_view s, mode_t mode, bool sync)
+void writeFile(const Path & path, PathView s, mode_t mode, bool sync)
 {
     AutoCloseFD fd = toDescriptor(open(path.c_str(), O_WRONLY | O_TRUNC | O_CREAT
 // TODO
@@ -470,25 +469,26 @@ void deletePath(const Path & path)
 }
 
 
-Paths createDirs(const Path & path)
+Paths createDirs(PathView path)
 {
     Paths created;
     if (path == "/") return created;
 
     struct stat st;
-    if (STAT(path.c_str(), &st) == -1) {
+    auto path2 = Path { path.native() };
+    if (STAT(path2.c_str(), &st) == -1) {
         created = createDirs(dirOf(path));
-        if (mkdir(path.c_str()
+        if (mkdir(path2.c_str()
 #ifndef _WIN32 // TODO abstract mkdir perms for Windows
             , 0777
 #endif
             ) == -1 && errno != EEXIST)
             throw SysError("creating directory '%1%'", path);
         st = STAT(path);
-        created.push_back(path);
+        created.push_back(path2);
     }
 
-    if (S_ISLNK(st.st_mode) && stat(path.c_str(), &st) == -1)
+    if (S_ISLNK(st.st_mode) && stat(path2.c_str(), &st) == -1)
         throw SysError("statting symlink '%1%'", path);
 
     if (!S_ISDIR(st.st_mode)) throw Error("'%1%' is not a directory", path);
@@ -509,7 +509,7 @@ void deletePath(const Path & path, uint64_t & bytesFreed)
 
 AutoDelete::AutoDelete() : del{false} {}
 
-AutoDelete::AutoDelete(const std::string & p, bool recursive) : path(p)
+AutoDelete::AutoDelete(PathView p, bool recursive) : path(Path { p.native() })
 {
     del = true;
     this->recursive = recursive;
@@ -536,8 +536,8 @@ void AutoDelete::cancel()
     del = false;
 }
 
-void AutoDelete::reset(const Path & p, bool recursive) {
-    path = p;
+void AutoDelete::reset(PathView p, bool recursive) {
+    path = Path { p.native() };
     this->recursive = recursive;
     del = true;
 }
@@ -597,7 +597,7 @@ Path createTempDir(const Path & tmpRoot, const Path & prefix,
 
 std::pair<AutoCloseFD, Path> createTempFile(const Path & prefix)
 {
-    Path tmpl(defaultTempDir() + "/" + prefix + ".XXXXXX");
+    Path tmpl(defaultTempDir() / prefix + ".XXXXXX");
     // Strictly speaking, this is UB, but who cares...
     // FIXME: use O_TMPFILE.
     AutoCloseFD fd = toDescriptor(mkstemp((char *) tmpl.c_str()));
@@ -659,7 +659,7 @@ void copy(const fs::directory_entry & from, const fs::path & to, bool andDelete)
 {
 #ifndef _WIN32
     // TODO: Rewrite the `is_*` to use `symlink_status()`
-    auto statOfFrom = lstat(from.path().c_str());
+    auto statOfFrom = lstat(from.path());
 #endif
     auto fromStatus = from.symlink_status();
 
diff --git a/src/libutil/file-system.hh b/src/libutil/file-system.hh
index 0c4e7cfdd489..8f94ae81ba67 100644
--- a/src/libutil/file-system.hh
+++ b/src/libutil/file-system.hh
@@ -73,25 +73,25 @@ Path canonPath(PathView path, bool resolveSymlinks = false);
  * immediate child thereof (e.g., `/foo`), this means `/`
  * is returned.
  */
-Path dirOf(const PathView path);
+Path dirOf(PathView path);
 
 /**
  * @return the base name of the given canonical path, i.e., everything
  * following the final `/` (trailing slashes are removed).
  */
-std::string_view baseNameOf(std::string_view path);
+PathView baseNameOf(PathView path);
 
 /**
  * Check whether 'path' is a descendant of 'dir'. Both paths must be
  * canonicalized.
  */
-bool isInDir(std::string_view path, std::string_view dir);
+bool isInDir(PathView path, PathView dir);
 
 /**
  * Check whether 'path' is equal to 'dir' or a descendant of
  * 'dir'. Both paths must be canonicalized.
  */
-bool isDirOrInDir(std::string_view path, std::string_view dir);
+bool isDirOrInDir(PathView path, PathView dir);
 
 /**
  * Get status of `path`.
@@ -156,7 +156,7 @@ void readFile(const Path & path, Sink & sink);
 /**
  * Write a string to a file.
  */
-void writeFile(const Path & path, std::string_view s, mode_t mode = 0666, bool sync = false);
+void writeFile(const Path & path, PathView s, mode_t mode = 0666, bool sync = false);
 
 void writeFile(const Path & path, Source & source, mode_t mode = 0666, bool sync = false);
 
@@ -223,10 +223,10 @@ class AutoDelete
     bool recursive;
 public:
     AutoDelete();
-    AutoDelete(const Path & p, bool recursive = true);
+    AutoDelete(PathView p, bool recursive = true);
     ~AutoDelete();
     void cancel();
-    void reset(const Path & p, bool recursive = true);
+    void reset(PathView p, bool recursive = true);
     operator Path() const { return path; }
     operator PathView() const { return path; }
 };
@@ -245,13 +245,13 @@ typedef std::unique_ptr<DIR, DIRDeleter> AutoCloseDir;
 /**
  * Create a temporary directory.
  */
-Path createTempDir(const Path & tmpRoot = "", const Path & prefix = "nix",
+Path createTempDir(PathView tmpRoot = "", PathView prefix = "nix",
     bool includePid = true, bool useGlobalCounter = true, mode_t mode = 0755);
 
 /**
  * Create a temporary file, returning a file handle and its path.
  */
-std::pair<AutoCloseFD, Path> createTempFile(const Path & prefix = "nix");
+std::pair<AutoCloseFD, Path> createTempFile(PathView prefix = "nix");
 
 /**
  * Return `TMPDIR`, or the default temporary directory if unset or empty.
@@ -261,7 +261,7 @@ Path defaultTempDir();
 /**
  * Used in various places.
  */
-typedef std::function<bool(const Path & path)> PathFilter;
+typedef std::function<bool(PathView path)> PathFilter;
 
 extern PathFilter defaultPathFilter;
 
diff --git a/src/libutil/fs-sink.cc b/src/libutil/fs-sink.cc
index 91070ea89a9a..710241ef8ae0 100644
--- a/src/libutil/fs-sink.cc
+++ b/src/libutil/fs-sink.cc
@@ -71,6 +71,7 @@ static GlobalConfig::Register r1(&restoreSinkSettings);
 
 void RestoreSink::createDirectory(const Path & path)
 {
+<<<<<<< HEAD
     Path p = dstPath + path;
     if (
 #ifndef _WIN32 // TODO abstract mkdir perms for Windows
@@ -80,6 +81,15 @@ void RestoreSink::createDirectory(const Path & path)
 #endif
         )
         throw NativeSysError("creating directory '%1%'", p);
+||||||| parent of 25ef34583 (Make `Path` `std::filesystem::path` not `std::string`)
+    Path p = dstPath + path;
+    if (mkdir(p.c_str(), 0777) == -1)
+        throw SysError("creating directory '%1%'", p);
+=======
+    Path p = dstPath / path;
+    if (mkdir(p.c_str(), 0777) == -1)
+        throw SysError("creating directory '%1%'", p);
+>>>>>>> 25ef34583 (Make `Path` `std::filesystem::path` not `std::string`)
 };
 
 struct RestoreRegularFile : CreateRegularFileSink {
@@ -92,7 +102,7 @@ struct RestoreRegularFile : CreateRegularFileSink {
 
 void RestoreSink::createRegularFile(const Path & path, std::function<void(CreateRegularFileSink &)> func)
 {
-    Path p = dstPath + path;
+    Path p = dstPath / path;
     RestoreRegularFile crf;
     crf.fd =
 #ifdef _WIN32
@@ -143,7 +153,7 @@ void RestoreRegularFile::operator () (std::string_view data)
 
 void RestoreSink::createSymlink(const Path & path, const std::string & target)
 {
-    Path p = dstPath + path;
+    Path p = dstPath / path;
     nix::createSymlink(target, p);
 }
 
diff --git a/src/libutil/json-utils.hh b/src/libutil/json-utils.hh
index 08c98cc8c0d4..302db5ce4036 100644
--- a/src/libutil/json-utils.hh
+++ b/src/libutil/json-utils.hh
@@ -7,6 +7,8 @@
 
 #include "types.hh"
 
+#include "file-path.hh"
+
 namespace nix {
 
 const nlohmann::json * get(const nlohmann::json & map, const std::string & key);
@@ -62,6 +64,9 @@ struct json_avoids_null<bool> : std::true_type {};
 template<>
 struct json_avoids_null<std::string> : std::true_type {};
 
+template<>
+struct json_avoids_null<Path> : std::true_type {};
+
 template<typename T>
 struct json_avoids_null<std::vector<T>> : std::true_type {};
 
diff --git a/src/libutil/linux/cgroup.hh b/src/libutil/linux/cgroup.hh
index 783a0ab87422..4124b098188f 100644
--- a/src/libutil/linux/cgroup.hh
+++ b/src/libutil/linux/cgroup.hh
@@ -4,7 +4,7 @@
 #include <chrono>
 #include <optional>
 
-#include "types.hh"
+#include "file-path.hh"
 
 namespace nix {
 
diff --git a/src/libutil/types.hh b/src/libutil/types.hh
index c86f52175d52..c6f821024125 100644
--- a/src/libutil/types.hh
+++ b/src/libutil/types.hh
@@ -18,14 +18,6 @@ typedef std::set<std::string> StringSet;
 typedef std::map<std::string, std::string> StringMap;
 typedef std::map<std::string, std::string> StringPairs;
 
-/**
- * Paths are just strings.
- */
-typedef std::string Path;
-typedef std::string_view PathView;
-typedef std::list<Path> Paths;
-typedef std::set<Path> PathSet;
-
 typedef std::vector<std::pair<std::string, std::string>> Headers;
 
 /**
diff --git a/src/libutil/users.cc b/src/libutil/users.cc
index d546e364f508..c6b93eb88c09 100644
--- a/src/libutil/users.cc
+++ b/src/libutil/users.cc
@@ -22,7 +22,7 @@ std::vector<Path> getConfigDirs()
 {
     Path configHome = getConfigDir();
     auto configDirs = getEnv("XDG_CONFIG_DIRS").value_or("/etc/xdg");
-    std::vector<Path> result = tokenizeString<std::vector<std::string>>(configDirs, ":");
+    std::vector<Path> result = tokenizeString<std::vector<Path>>(configDirs, ":");
     result.insert(result.begin(), configHome);
     return result;
 }
diff --git a/src/libutil/users.hh b/src/libutil/users.hh
index 153cc73fdae4..f778167dce24 100644
--- a/src/libutil/users.hh
+++ b/src/libutil/users.hh
@@ -1,7 +1,7 @@
 #pragma once
 ///@file
 
-#include "types.hh"
+#include "file-path.hh"
 
 #ifndef _WIN32
 # include <sys/types.h>
diff --git a/src/nix-build/nix-build.cc b/src/nix-build/nix-build.cc
index 46533b34bd05..460c54ddca8a 100644
--- a/src/nix-build/nix-build.cc
+++ b/src/nix-build/nix-build.cc
@@ -308,7 +308,8 @@ static void main_nix_build(int argc, char * * argv)
                     absolute = canonPath(absPath(i), true);
                 } catch (Error & e) {};
                 auto [path, outputNames] = parsePathWithOutputs(absolute);
-                if (evalStore->isStorePath(path) && hasSuffix(path, ".drv"))
+                if (evalStore->isStorePath(PathView { path })
+                    && hasSuffix(path, ".drv"))
                     drvs.push_back(PackageInfo(*state, evalStore, absolute));
                 else
                     /* If we're in a #! script, interpret filenames
@@ -317,7 +318,7 @@ static void main_nix_build(int argc, char * * argv)
                         state->parseExprFromFile(
                             resolveExprPath(
                                 lookupFileArg(*state,
-                                    inShebang && !packages ? absPath(i, absPath(dirOf(script))) : i))));
+                                    inShebang && !packages ? absPath(i, absPath(dirOf(script))) : Path { i }))));
             }
         }
 
diff --git a/src/nix-channel/nix-channel.cc b/src/nix-channel/nix-channel.cc
index 9f7f557b59db..6c1c49f85490 100644
--- a/src/nix-channel/nix-channel.cc
+++ b/src/nix-channel/nix-channel.cc
@@ -107,7 +107,7 @@ static void update(const StringSet & channelNames)
             // no need to update this channel, reuse the existing store path
             Path symlink = profile + "/" + name;
             Path storepath = dirOf(readLink(symlink));
-            exprs.push_back("f: rec { name = \"" + cname + "\"; type = \"derivation\"; outputs = [\"out\"]; system = \"builtin\"; outPath = builtins.storePath \"" + storepath + "\"; out = { inherit outPath; };}");
+            exprs.push_back("f: rec { name = \"" + cname + "\"; type = \"derivation\"; outputs = [\"out\"]; system = \"builtin\"; outPath = builtins.storePath \"" + storepath.native() + "\"; out = { inherit outPath; };}");
         } else {
             // We want to download the url to a file to see if it's a tarball while also checking if we
             // got redirected in the process, so that we can grab the various parts of a nix channel
diff --git a/tests/unit/libstore/machines.cc b/tests/unit/libstore/machines.cc
index 9fd7fda54cc3..d984b5fa6761 100644
--- a/tests/unit/libstore/machines.cc
+++ b/tests/unit/libstore/machines.cc
@@ -143,7 +143,7 @@ TEST(machines, getMachinesWithCorrectFileReference) {
     auto path = absPath("tests/unit/libstore/test-data/machines.valid");
     ASSERT_TRUE(pathExists(path));
 
-    settings.builders = std::string("@") + path;
+    settings.builders = std::string("@") + path.native();
     Machines actual = getMachines();
     ASSERT_THAT(actual, SizeIs(3));
     EXPECT_THAT(actual, Contains(Field(&Machine::storeUri, EndsWith("nix@scratchy.labs.cs.uu.nl"))));