Burg Freundsberg is a castle in Tyrol, Austria, that was constructed in the year of 1150 by the lords of Freundsberg. Originally the castle consisted out of a single keep, which is still intact up to this date. The chapel next to it was built afterwards in the year 1117. In 1467 the castle was sold to Archduke Sigismund of Austria, who rebuilt the castle and called it Sigismundruh for the duration of his reign.
From 1634/37 on, the castle was retrofitted as a "castle church" or Schlosskirche. (Not to be confused with the All Saints' Church, Wittenberg, which is also referred to as a Schlosskirche.) After passing to several other owners from 1812 on, Castle Freundsberg became a property of the municipality of Schwaz. They restored the castle from 1966 onwards.
Since 1948 is the castle a museum where the history of the city Schwaz and the silver mining industry in this region is documentated.