Building the gothic church of St. Peter's started in about 1220, and it was enlarged bit by bit until the 15th century. Thus it evolved from a basilica, which originally had three naves, into the only major church with five naves of identical height. The steeple got its four characteristic small corner towers not before 1417, when it was raised by two additional floors. The rich interior was completely destroyed when St. Peter's burned out in a bomb raid in 1942. The damage was extremely heavy, reconstruction was not finished until 1987. Today, changing exhibitions of contemporary art and numerous concerts take place in St. Peter's. Admission to the church is free. A lift leads up the steeple to a platform providing an excellent view of the Old Town.