The Prague Castle complex is enormous, with an area totaling approximately 753,473 square feet. That makes it the largest ancient castle in the world, according to the Guinness Book of World The 40,000 to 70,000 skeletons within Sedlec Ossuary (aka Kostnice Ossuary Beinhaus) in the Czech Republic welcome you, quite literally, with open arms. Known to most as “the Bone Church,” it The 10 Best Apartments For Rent in Prague, Czech Republic. Prague Violet Apartment: 588 € Prague Penthouse with rooftop jacuzzi (410 m2): 417 € Prague Cozy Studio IP Pavlova: 683 € Prague Atelier Loretánská no.5 / 150m from Prague Castle: 638 € Prague 2bds apartment near main station: 1176 € Prague U Pujcovny: 2277 € According to the Guinness Book of World Records, Prague Castle is the largest ancient castle in the world. However, we only toured part of it. Much of the castle is government offices, including the office of the president of the Czech Republic. We were lucky enough to catch the changing of the guard on our entry into the castle. 21. Athenry Castle. Athenry is one of the most notable surviving medieval walled towns in Ireland and, together with its tower house, is a national monument. Parts of the original enclosure wall of the castle survive along with the 13th-century battlements, and the large rectangular hall keep with base batter. Since the separation of the Czech Republic and Slovakia in 1992, it serves as the official residence of the Czech Head of State but it is open to visitors. Burghausen Castle, Germany The third biggest castle in Europe and Europe's longest castle complex dates back to the 10th century. The world's largest palace, located in the heart of Beijing, has an equally impressive moat. A 170-foot-wide, Český Krumlov Castle, Czech Republic Climbing the 287 stairs also opens a view of the tower's bells, including "Sigmund", the largest bell in the Czech Republic. Riding Hall of the Castle The imposing riding hall at the Prague Castle from the 17th century impresses with its Baroque facade decorated with stucco reliefs. Top ways to experience Zámek Mikulov and nearby attractions. Private transfer from Prague to Vienna with 2h stop in Mikulov. 0 reviews. Transportation Services. from. $143.71. per adult (price varies by group size) Fullday Private Tour in Lednice & Valtice with Wine Tasting. 4. GeAIA.