The Hopfen castle ruins are located at the northern end of the Hopfensee on a plateau about 100 m high. The history of the castle is difficult to discover. Probably built in the early to mid-12th century, possibly as early as the 11th century, it passed to the Bishopric of Augsburg at the end of the century and gradually fell into disrepair from 1322 onwards when the custodianship was moved from the castle to the new palace in Füssen, although extensions were also made from time to time. At the beginning of the 18th century, the decay was accelerated by the fact that huge amounts of building material from the castle were used for the St. Mang monastery in Füssen.
As late as 1999, only a few remains of the castle ruins could be seen in the surrounding area. Until around 2007, attempts were made to uncover the remains and thus secure the state visible today.
From the castle ruins you have a beautiful view to the south and southwest over the Hopfensee and to the mountains. To the north and east, the plateau is surrounded by forest, with numerous hiking trails inviting you to take tours.
Directly to the east, the castle path leads from the ruins down towards the town of Hopfen am See and the beach promenade of the Hopfensee.