Ehemaliges Schloss Sonderbuch (Schlossberg)

Zwiefalten, Germany, Germany

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Ehemaliges Schloss Sonderbuch, commonly called Schlossberg, is the site of a lost hilltop castle located southeast of Sonderbuch (a village now part of Zwiefalten) in Baden-Württemberg, Germany.

Built likely in the 11th century as a motte-and-bailey castle (Turmhügelburg) by the Lords of Sonderbuch on what may have been a pre-Christian burial mound, the fortress stood at about 675 meters above sea level on a prominent hill that still bears the name Schlossberg (“castle mountain”).

The castle was abandoned and completely disappeared over time, leaving no above-ground ruins today, but the location remains a documented historic site. Sonderbuch itself was first mentioned around 1100 and passed to Zwiefalten Abbey in 1432, and the area is now a quiet rural village with around 160 residents, known for its 1861 town hall, a 17th-century Leonard Chapel, and a Stations of the Cross path leading toward Zwiefalten.