Philppstein
Not much remains of Philippstein, a castle just to the south of Braunfels.

Right, the castle as seen from the town below.

These photos were taken in 2008.
Graf Philipp I von Nassau-Saarbrucken (1371-1429) had this castle started in 1390 when he was not yet 20 years old as a border outpost between the Lords of Solms and their rivals at Braunfels.  On the east side the castle was protected by a dry moat, while on the west and north it was protected by the steep slopes of the hill on which it rested.  The castle's strategic value was proven in 1406 when Count Johann III engaged in a feud with the Archbishop of Trier, Werner von Trier.  The Count and 24 of his knights fell captive in the fight.  The castle would later serve as an administrative center for the region in the 1500s.  Like many other castles, it soon became too expensive to maintain and was allowed to crumble to a ruin.

While the keep and some of the walls of the inner ward have been preserved, the outer ward and its wall have largely vanished.  Parts of the dry moat are still visible.
Unfortunately, when we arrived the castle was closed.  We could walk up the reconstructed wooden steeps to peer into the tower (above) but beyond that there was little left to look at.

However, the site does provide a spectacular view of Braunfels (below).