Bremen can boast a UNESCO world heritage site: the Town Hall and the Roland statue standing in front of it on the market square. The magnificent Town Hall is a testimony to the self-confidence of the Hanseatic city and its citizens. The Roland, being eleven meters high, is the biggest preserved statue of the Middle Ages in Germany. It depicts a knight with the imperial coat of arms on his shield, a reminder of the time when Bremen first became a free imperial city. At the Town Hall, there is also a monument to the Bremen Town Musicians from the fairy tale by the Brothers Grimm, who made Bremen world-famous. The Tanztheater Bremen, the Bremer Shakespeare Company, the Deutsche Kammerphilharmonie and the Theater Bremen, which had been voted "Opera House of the Year" in 2007, enjoy an excellent reputation. Every year in September, the Bremen Music Festival attracts an international audience of lovers of old and new music. Bremen's museum landscape also leaves little to be desired. Its spectrum ranges from art and design to antiquity, from the history of shipbuilding to astronomy. The Überseemuseum is one of the most important ethnological museums in Europe. The Gothic churches in Bremen's old town are definitely worth seeing. St. Peter's Cathedral, the oldest church building in the city, is famous for the mummies that were found in the eastern crypt, the "lead cellar".