Špilberk Castle looms over Brno from a ridge west of the old town, its silhouette one of the most recognisable in Moravia. The castle dates back to the 13th century and has served as a royal residence, a military fortress, and — most notoriously — a Habsburg prison. Today it houses the Brno City Museum, with permanent exhibitions on the castle's history, the history of Brno, and the Habsburg prison system.
The most visited part is the casemates network beneath the castle: a maze of vaulted underground corridors and cells where political prisoners were held. Separate tours run for different sections; the deepest cells, used for the most serious offenders, are among the most atmospheric spaces in the building. The castle park surrounding the fortress is a pleasant place to walk and offers the best views across Brno and the surrounding South Moravian landscape.