Brno is the second largest city in the Czech Republic by population and area, the largest Moravian city, and the historical capital city of the Margraviate of Moravia. Brno is the administrative center of the South Moravian Region in which it forms a separate district. The city lies at the confluence of the Svitava and Svratka rivers and has about 400,000 inhabitants; Brno is the seat of judicial authority of the Czech Republic – it is the seat of the Constitutional Court, the Supreme Court, the Supreme Administrative Court, and the Supreme Public Prosecutors Office. The city is also a significant administrative centre. It is the seat of a number of state authorities, including the Ombudsman, Brno Exhibition Centre ranks among the largest exhibition centres in Europe . The most visited sights of the city include the Špilberk castle and fortress and the Cathedral of Saints Peter and Paul on Petrov hill, two medieval buildings that dominate the cityscape and are often depicted as its traditional symbols. The other large preserved castle near the city is Veveří Castle by Brno Reservoir. This castle is the site of a number of legends, as are many other places in Brno. Another architectural monument of Brno is the functionalist Villa Tugendhat which has been included on the UNESCO list of World Heritage Sites. One of the natural sights nearby is the Moravian Karst.