Allmendingen Castle, Renaissance castle in Allmendingen bei Bern, Switzerland

Allmendingen Castle is a late Gothic Renaissance country estate built in 1607 as the summer residence of Kaspar von Graffenried. Its defining feature is an octagonal stair tower set outside the main building, whose door bears the year 1607. The house has a hipped half-hip roof, and in the 18th century it was expanded into a campagne with a symmetrical north-south axis, a central block and two side wings around an entrance courtyard.

The original Allmendingen Castle was probably built in the High Middle Ages for the Lords of Allmendingen; Rudolf von Alwandingen is recorded between 1239 and 1256, and in 1256 the lords sold Allmendingen and Märchligen to Interlaken Monastery. The old castle fell into ruin, described as a broken castle by Thomas Schöpf in the 16th century and still visible in 1729. The present castle was built in 1607 as a summer residence for Kaspar von Graffenried, with a tower door bearing that year. In the 18th century Schultheiss Isaak Steiger and his son Franz Ludwig expanded it into a campagne.

The name Allmendingen comes from the Lords of Allmendingen, documented only in the 13th century; Rudolf von Alwandingen appears in records between 1239 and 1256. The estate later passed to Bern after the 1528 Reformation secularised Interlaken Monastery. A door on the tower carries the year 1607, and the tower once had a high pointed roof, later replaced by a lower one.

The castle stands in Allmendingen bei Bern, on the road toward Thun, with the estate farm adjoining the north side and a park with old trees around the ensemble. The entrance courtyard lies between the central block and two side wings. The building is privately owned and was offered for sale in 2023, so visitors should view it from outside.

Winston Churchill visited the property in September 1946, a documented event that brought international attention to the location. This visit remains one of the most notable occurrences in the place's modern history.