St. Peter's Church was built in the 9th century AD, making it the oldest church in Zurich. The church changed significantly after renovations in the thirteenth century and again in the early eighteenth century AD. Inside, there are stunning Baroque ceilings, a choir in Romanesque architecture, an elaborately carved pulpit, and interior frescoes telling the stories of the martyrs and the Virgin Mary. One of its most important distinguishing features is the large clock on top of its towering tower. It is one of the landmarks that tourists coming to the city must visit.