On top of the hill there is a romanesque rotunda of Saint George, which is one of the oldest buildings in the Czech Republic. This is mentioned for the first time in 1126, when Soběslav I, Duke of Bohemia, commemorating his victory at the Battle of Chlumec, where he defeated Holy Roman Emperor Lothair III, had the rotunda repaired and extended by the western circular tower. The rotunda's current appearance is the result of a purist reconstruction during the 1870s.