Dein Browser kann keine 3D-Grafik im Web darstellen. Aktualisiere deinen Browser, oder schalte die Hardwarebeschleunigung in den Browser-Einstellungen ein.
This map renders the indoor data that is normally invisible on OpenStreetMap, provided by indoor=. Zoom in to a bigger train station for example, and you'll see what is mapped there.
Learn more about how to tag elements in OSM for indoor maps.