The remains of the Castle can be visited
Neuburg Castle (Ruin) (Untervaz)

Southwest of Untervaz in the Swiss canton of Graubünden is the Neuburg ruin. It is situated on a steep rocky outcrop about 50 meters above the Rhine valley floor and has a palas which is among the largest in Raetia.
History+
The construction of Neuburg is presumed to have taken place around 1300, likely by the Thumb von Neuburg family, whose ancestral seat was in Vorarlberg. The castle was first documented in 1345 in a contract between the brothers Siegfried and Johann Thumb and the Bishop of Chur, to whom they had to keep the castle open for three years. In 1360, Neuburg passed as collateral to the Buwix brothers, who served Austria. From 1385, the Thumb von Neuburg family was again in possession of the complex. Around 1400, Johann von Neuburg submitted to the feudal lordship of the Bishop of Chur.
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: 46.9127, 9.5442