The remains of the Castle can be visited
Sigmundsburg Castle

On an island in Lake Fernstein, amidst dense forests, lies the castle ruin Sigmundsburg. The castle is located in Nassereith-Fernstein in the Imst district, Tyrol, Austria, at an elevation of approximately 976 meters above sea level.
History+
Duke Sigmund the Rich in Coin had Sigmundsburg built, likely as a tribute to his first wife, the Scottish princess Eleonore, whom he married in 1449. After its completion in 1463, Eleonore moved into the castle, preferring it over the Hofburg in Innsbruck. The Duke probably used it for hunting parties and fishing in the lake. Occasionally, the secluded castle also served as a refuge, for example in 1463/65 from a plague and in 1478 from the Turks.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://commons.wikimedia.org/wiki/File:Fernsteinsee_Sigmundsburg-Kapelle.jpg
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: 47.3451, 10.8238