Tannenburg, Spur castle in Bühlertann, Germany.

Tannenburg is a spur castle perched on a western ridge of the Ellwanger Berge mountains, overlooking the Bühlertal valley below. It features three successive defensive moats and a large accessible shield wall that demonstrate its former fortifications.

The Benedictine Abbey of Ellwangen built this border fortress between the 11th and 12th centuries as a strategic outpost. Its first documented mention appears in regional records from 1223.

The chapel inside is dedicated to Saint Maria Magdalena and shows Gothic and Renaissance features in its stone walls. Visitors can still see these architectural details while walking through the grounds today.

The property operates today as a school landhome and educational farm where visitors can learn about agriculture and medieval history. Access to the fortifications and shield wall is available to tourists, providing good views of the overall structure.

The three neck ditches are dry, cut into the ridge rather than filled with water. The 4-metre-thick shield wall narrows the spur to under 100 metres before the gate, and a summer lime tree in the courtyard is listed as a natural monument (ID 81270120001).