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

The Falkenstein Ruin, located in Pfronten in the Ostallgäu region of Bavaria, is a medieval architectural site. As Germany's highest castle ruin, it stands at approximately 1203 meters above sea level, offering a view of the Vils Valley and the Tannheim Mountains. Its exposed location once made it a widely visible symbol of power and dominion.
History+
Around 1280, Count Meinhard II of Tyrol, who asserted claims to the Staufer inheritance in the Ostallgäu, ordered the construction of the “castrum Pfronten.” The first documented mention occurred in 1290, with the name Falkenstein becoming common only in the 15th century. Shortly thereafter, the castle passed to Augsburg Bishop Wolfhard. Until 1582, it served as the seat of the Augsburg bailiffs, who, however, often resided in the valley due to the altitude.
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: 47.5694, 10.5913