The remains of the Castle can be visited
Buttenhausen Castle (Ruin)

The Buttenhausen Ruin, a historic spur castle, is also known as the old castle on the mountain. Its remains rise above the district of Buttenhausen. Although only fragments of walls remain today, they were once a significant complex in the Reutlingen region.
History+
The first documented mention of Buttenhausen Castle dates back to 1389. At that time, Knight Friedrich III von Gundelfingen sold the Vogtland of the village to Konrad, who served as provost of the St. Maria monastery in Güterstein near Urach. In 1469, the castle was owned by the Lords of Stein. Later, in 1569, it changed hands again when Wolf Dietrich von Stein sold the complex to Eberhard von Gemmingen zu Bürg. From 1812 onwards, the castle began to decay, although the stables were still used for a time. In the same year, the castle was owned by Baron von Münch, and in 1825, the granary still served its original purpose.
Source: Wikipedia · Licence: CC BY-SA 4.0
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 48.3625, 9.4796