The castle stands on a ledge looking downstream from the riverside at Sankt Goar.
It used to be and still is, however, comfortably and commonly contracted to "die [Burg] Katz" ("the [Castle] Cat").
As such, it is popularly linked with Burg Maus ("the [Castle] Mouse"), which was indeed erected in closest possible vicinity as its military counterpart.
The castle is of compact layout, consisting mainly of a great hall and a massive bergfried, originally 40 metres tall, on the uphill side.
[1] Katz Castle and its surroundings are the place of action for the Belgian comic book L'Orgue du Diable in the Yoko Tsuno series by Roger Leloup.