Sweden's High Court in Riddarholmen's 1640s school

Riddarholmen's oldest building, Östra Gymnasiehuset, was expanded in the 1640s by Gustaf Adam Banér. It is a state-owned cultural heritage building since 1935, with remnants of the cloister wall. It was built on the foundation and walls of Gråbrödraklostret and has a star-vaulted room attributed to Albertus Pictor. After serving as a school, it is now the seat of Svea hovrätt, Sweden's high court. In the 1730s, it was the residence of Hedvig Taube, the mistress of King Fredrik I.

Sources: Wikipedia, OpenStreetMap, Wikidata, Wikimedia Commons