The remains of the Castle can be visited
Solavers Castle (Ruin) (Seewis)

The Solavers Ruin, a former castle, is located above Seewis in the Prättigau region of Canton Graubünden, Switzerland. A striking feature is a long defensive wall that once protected the complex.
History+
The origins of the complex date back to the Romanesque period, when a church dedicated to the Virgin Mary was built here, serving as the mother church for Seewis and Fanas. In the 13th century, Solavers became a center of power in the lower Prättigau when Ulrich von Aspermont took possession of the castle. Through a division of property, the complex passed to the Counts of Toggenburg in 1344, who occasionally resided there. After the death of the last Toggenburg, Friedrich VII, in 1436, Solavers changed hands several times, including Wilhelm von Montfort-Tettnang and Heinrich von Sax-Misox. Later, Count Hugo von Werdenberg sold the castle to Sigmund of Austria. With the Reformation in the Prättigau, the Marienkirche was abandoned, although it continued to exist as a filial church until the late Middle Ages.
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: 46.9833, 9.6444