Almost all Todi's main medieval monuments-- the co-cathedral church (Duomo), the Palazzo del Capitano, the Palazzo del Priore and the Palazzo del Popolo --front on the main square on the lower breast of the hill: the piazza is thus one of the most picturesque in Italy and is often used as a movie set. The whole landscape is sited over some huge ancient Roman cisterns, with more than 500 pits, which remained in use until 1925.