The medieval royal palace that once covered the castle hill is now partially excavated and open as a museum integrated into the lower levels of the hilltop complex. The recovered stonework shows a sophisticated Gothic building programme, and the Renaissance additions commissioned by Matthias Corvinus in the 15th century — red marble doorways, carved window frames — give a sense of the palace's original elegance.
The palace museum holds a substantial collection of architectural fragments, wall paintings, and medieval stonework found during excavations. The highlight is the Romanesque chapel, whose surviving walls date from the 12th century and represent the oldest intact space on the hill. A terrace overlooking the Danube allows views across to Slovakia in one direction and down toward the town in the other.