Settlers have always been drawn to this site overlooking a ford across the river. Initially occupied by Germanic and Slav tribes, in the 10C it fell into the hands of the Premyslide sovereigns of Bohemia who established a fortress. In 1179, Emperor Frederick Barbarossa undertook the construction of the current imperial castle. A few elements remain today such as the basalt keep, known as the Black Tower (Cerná vež) and the upper room of the chapel adorned with columns, carved capitals and ribbed vaulting.