Of the Führerhauptquartier nothing can be visited
Führerhauptquartier Adlerhorst

The Führerhauptquartier Adlerhorst, a military complex, was located in Langenhain-Ziegenberg, Hesse. It was designed as a command post, but was not used as planned.
History+
Between September 1939 and August 1940, the Adlerhorst bunker complex was constructed under the direction of the Organisation Todt, based on designs by Albert Speer. Initially intended for the leadership of the Third Reich, the facility was rejected by Adolf Hitler in February 1940. Instead, it later served as a command post for the Ardennes Offensive, with Hitler himself occupying the quarters from December 11, 1944, to January 15, 1945. Prior to this, Ziegenberg Castle had already served as the headquarters for the Commander-in-Chief West from October 1944. The military structures of Adlerhorst also included Ziegenberg Castle, and above-ground parts of the complex were camouflaged as residential houses.
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: 50.3671, 8.6258