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

Southwest of the hamlet of Baltenstein in the municipality of Betzigau lies the Baltenstein ruin, once a small castle complex.
History+
Around the year 1200, the Lords of Stein, who later named themselves after the location, built Baltenstein Castle. As early as 1239, Heinrich von Stein was mentioned as a vassal of the Kempten Abbey. In 1276, the Lords of Baldenstein appeared. The castle was a fief of the Kempten Abbey. After 1289, the family of the Lords of Stein died out with Heinrich von Stein, and the complex passed to the Schenken von Sulzberg. After its destruction in 1370, the castle came into the possession of the Kempten citizen Ruf Schellang and in 1439 to the Kempten Hospital. In the mid-16th century, the castle was abandoned and gradually fell into disrepair.
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: 47.7220, 10.4011