Overlooking Graz, this formerly fortified hill rises to a height of 473m (1,552 ft.) above sea level. As mentioned above, in 1809 the fortifications were leveled as part of the terms of Austria's treaty with Napoleon. You can take a cable railway (tel. 0316/887413) to the restaurant on top of the hill, or you can climb the winding stairs. From the top, you'll be able to look down on the city and its environs. Guided tours of the citadel start from the bell tower opposite the upper station of the cable railway. Although you can visit the Schlossberg year-round, no guided tours are offered from November to April.
During the summer, concerts are held on a wooden stage constructed within the castle's ramparts. Tickets are not cheap -- from 12€ to 75€ ($19-$120). Upcoming concerts are announced every season. For more information about schedules, call the tourist office.
The Uhrturm (Clock Tower) on the citadel is a curiosity; it rises above the walls of the former Citizens' Bastion. It acquired its appearance between 1555 and 1556, when the original Gothic tower was remade in the Renaissance style: The builders added a circular wooden gallery with oriels and four huge clock faces.