Only Piazza San Marco is larger than this square, and the echo of children's voices bouncing off the surrounding palaces makes the space seem even bigger. Campo San Polo once hosted bull races, fairs, military parades, and packed markets, and now comes especially alive on summer nights, when it's home to the city's outdoor cinema. The Chiesa di San Polo has been restored so many times that little remains of the original 9th-century church, and sadly, 19th-century alterations were so costly that the friars sold off many great paintings to pay bills. Though Giambattista Tiepolo is represented here, his work is outdone by 16 paintings by his son Giandomenico (1727–1804), including the Stations of the Cross in the oratory to the left of the entrance. The younger Tiepolo also created a series of expressive and theatrical renderings of the saints. Look for altarpieces by Tintoretto and Veronese that managed to escape auction. San Polo's bell tower (begun 1362) remained unchanged through the centuries—don't miss the two lions playing with a disembodied human head and a serpent that guard it. Tradition has it that the head refers to that of Martin Falier, the Doge executed for treason in 1355.