Prague Castle is the most famous Czech castle (originally an early medieval fortified settlement) standing on a rocky promontory over the Vltava River in the center of Prague, on the hill of Opyš. From the 9th century it was the seat of Czech princes, later kings, and since 1918 it has been the seat of the President of the Republic. Twice in history he became the main residence of the Emperor of the Holy Roman Empire. Gradual extensions and modifications arose from a fortified settlement built in the 9th century with its dimensions of 570 m in length and 128 m in width, one of the largest castle complexes in the world. The area of the castle is usually 7,28 hectares, but today it is the subject of disputes. It is considered not only a symbol of the city, but also the Czech statehood and the largest ancient castle in the world. Part of the castle is the Cathedral of St. Vitus, the traditional place of crowning Czech kings and their last rest. Besides many Czech monarchs (including four emperors), Prague bishops and archbishops, clergy, nobility and other people connected with the Prague court, some saints are buried in the cathedral – a large part of the Czech patrons (Saint Wenceslas, Vít, Vojtěch, Zikmund or Jan Nepomuk). There are also Czech crown jewels.