The remains of the castle can be visited
Gräfenberg Castle
The Gräfenberg castle ruin is on an outlier mountain in the Bavarian Spessart. Once a complex of the Counts of Rieneck, today only a few remnants remain.
History+
The summit of Gräfenberg was already used in the Neolithic Age as a hunting ground and for timber extraction, as evidenced by finds of arrowheads. However, a Neolithic settlement could be ruled out. In the Early Middle Ages, a ditch and rampart system with a fortified settlement was located here. The castle was built shortly before 1260 by the Counts of Rieneck. It featured an approximately two-meter-thick curtain wall, integrated into the early medieval ring wall, and likely rose over ten meters high. The castle was razed and abandoned only a few years after its construction.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://de.wikipedia.org/wiki/Datei:Gr%C3%A4fenberg_Mauer.JPG
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: 50.0324, 9.2306