Castle Gewerkenegg dominates the old core of Idrija. It was erected at the beginning of the 16th century to serve as the administrative headquarters and warehouse of the Idrija mine, then the second largest mercury mine in the world.
The now beautifully restored Renaissance complex experienced a Baroque renovation in the middle of the 18th century when the inner arcaded courtyard was created and painted with attractive decorative frescoes. The castle now houses the Idrija Museum, whose central exhibit-Five Centuries of Mercury Mining and the Town of Idrija-offers a survey of the half-millennium history of the oldest mining town in Slovenia. It also offers an exhibit of Idrija lace, a replica of a room in an Idrija miner's home, peasant frescoes, memorial rooms of the writer France Bevk and the politician Aleš Bebler, and a collection of paintings donated by the gallery owner Valentina Orsini Mazza.
The castle also provides rooms and a concert hall for the Idrija Music School.
 
Throughout the year, the museum organizes various events, presentations, and receptions in the castle hall. The Museum Evenings lecture series is especially popular. In summer, the Castle Evenings program of cultural events, mostly concerts, moves into the castle courtyard. For its ambitious and professional work, the museum was awarded the flattering title Best European Museum of Technical And Industrial Heritage by the European Museum Association in 1997.
Gewerkenegg castle (360°)

 
Special feature:
The only castle in Slovenia built not for feudal lords but for the needs of the mercury mine. It served as the mine’s administrative center for more than 400 years. Its arcaded courtyard is richly painted with frescoes.