Neuburg Castle (Ruin) (Untervaz)

Neuburg Castle is a ruined castle in Untervaz in the Canton of Graubünden in Switzerland. It is a Swiss heritage site of national significance.

Castle Neuburg was first built during the late 13th Century, most likely for the Baron Tumb von Neuburg (Vorarlberg). About 1450 it came under the control of Rudolf von Rappenstein, and at that time was known as Mötteli. In 1496 it was sold to the Bishop of Chur. Then, in 1577 the municipality bought the castle and associated barony. In the 16th Century, the site was abandoned and began to collapse.

The castle site includes the still visible rectangular keep, which is one of the largest in Raetia. The keep was four-stories tall and was about 12 x in size. North and west of the keep, the foundations and portions of the curtain wall and gatehouse are still visible. In the northern courtyard, there is a large round cistern. The castle was repeatedly expanded. The original structure included arcades, detached kitchens and sinks.

The walls were about 1.5 m thick at the base, though they thinned out as they rose. The inner courtyard was divided by walls into three similar sized sections. On the mountain side of the castle site, a 2 m high gate led to the middle section of the castle.