Cmurek Castle, Medieval castle in Trate, Slovenia.

Cmurek Castle stands on a steep cliff above the Mura River at Trate, opposite the Austrian town of Mureck. The two-storey building has an irregular ground plan with a Renaissance arcaded courtyard and residential wings; its core is still Romanesque, though 16th-century rebuilds obscured much of the original design. The chapel was built in 1340, and the imperial master builder Andrea Bertoletti added the courtyard arcades around 1590. The medieval tower was demolished in the late 18th century.

The fortress was first documented in 1148 as a holding of the Cmurek noble family. It passed through the Counts of Celje and later the Stubenberg family before ownership changed in 1931.

The Museum of Madness opened in the castle in 2013 (some sources say 2014) to keep alive the history of the former Institute for the Mentally and Nervously Ill at Trate. Its permanent displays include "Neskončne Trate norosti" (2022) on life and work in the institution after 1945, plus exhibitions on Romanesque and Gothic architecture in Slovenia. In 2023 the museum received a Valvasor honorary award.

The castle stands on a steep cliff above the Mura, directly by the bridge and the international border crossing to Mureck in Austria. The Amazonas of Europe cycling route passes the building, so it is easily reached by bike from either side of the border. The terrain around the cliff is steep.

The castle's psychiatric institution was the first and so far only social welfare institution in Slovenia closed for the purpose of deinstitutionalisation, in 2004, when residents moved to smaller housing communities. A 2020 documentary by director Amir Muratović, Muzej norosti, covers the institution's history and the museum's mission.