Cattedrale di San Pietro

Built over a 200-year period starting in the 12th century, this Romanesque–Gothic cathedral was commissioned by local boy-made-big Pope Gregory VII (Hildebrand of Sovana; c 1015–85). Its strangely positioned doorway is decorated with carvings of people, animals and plants, and its huge interior has a beauty that owes nothing to artworks and everything to the genius of its unknown architect.