Former Abbey Königsfelden, Medieval monastery in Windisch, Switzerland

The Former Abbey Königsfelden is a monastery complex in Windisch that once housed Franciscan friars and Poor Clare nuns in separate sections. The buildings display typical medieval architecture with a church, residential quarters, and a cloister.

Elizabeth of Carinthia founded the monastery in 1310 as a memorial to her husband, King Albert I of Germany, who was murdered near this location in 1308. The site remained an important religious center for centuries afterward.

The monastery church displays stained glass windows from the 14th century that rank among Switzerland's most valuable medieval artworks. Visitors can view these works in their original architectural setting and experience the artistic quality of that era.

The monastery church has belonged to Museum Aargau since 2009. The former Franciscan convent no longer stands; stone slabs set into the ground mark where its buildings were, and the surviving Archivgewölbe holds wall paintings of knights fallen at Sempach in 1386. The psychiatric clinic still occupies much of the complex, so visitors see the church, the archive vault and parts of the nuns' convent, including the cloister.

The psychiatric clinic that took over the site from 1868 was built partly by demolishing the Franciscan convent; only the so-called archive vault survived, and it holds wall paintings of knights fallen at the Battle of Sempach in 1386. Director Leopold Lindtberg filmed parts of Matto regiert here in 1947, based on Friedrich Glauser's novel drawing on his own time as a psychiatric patient.