The remains of the Castle can be visited
Dreienburg Castle (Ruin) (Lautenhausen)

The Dreienburg ruin, also known as Alter Keller, is a historical structure in Hesse. It sits atop the Dreienberg near Lautenhausen.
History+
The exact construction period of the Dreienburg is unknown, but it is presumed to have been built on behalf of Hersfeld Abbey as protection against Hessian influences. Its first documentary mention occurred in 1257, when a lord of the castle named Hertwig von Drigenberg was named. Later, in 1296, the name Wolprat de Drigenberck appeared in the annals. The last mention of the castle dates back to 1641.
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: 50.8644, 9.8769