Example game with jet fighter flying over landscape and cities provided by Melown Technologies's VTS geospatial software stack.
The VTS plugin also proved an implementation of shifting origin - a technique that allows to shift the real world to keep the player close enough to the origin of the unity world, which allows the player to fly over the entire globe.
The real world coordinates as well as unity world coordinates of the camera are shown on top of the screen.
Either download and install the VTS plugin from Asset Store: https://assetstore.unity.com/packages/tools/terrain/vts-landscape-streaming-plugin-125885
Or clone and build the VTS plugin from sources: https://github.com/melowntech/vts-browser-unity-plugin
Please note, this example game is developed together with the plugin and therefore it may depend on some features of the VTS plugin that are not yet published to the store, or vice-versa.