In place of today’s castle there first was only a watchtower, built at a prominent location on the basalt rock, which served as border guards against the Count of Nassau in the West. This was expanded and by a (residential) Palas and supplemented by another tower.
Something like in the small picture could have looked like the original core castle with Friedrichsturm (covered by the double-gabled Palas at the back left) and Altes Stock (right).
In the beginning the castle has probably existed out of these three buildings, which were surrounded by a wall. Until today you can see the Friedrichsturm (watchtower), see the Palas (with the Knight’s Hall) and the “Alter Stock” (former castle keep) and thus recognize the old castle of the 13th century in its basic features.