The Basilica of San Francesco alla Rocca is located in the city of Viterbo, inside there are the tombs of two popes, Clement IV and Adriano V. The sepulchral monuments of Clement IV and Adriano V are notable examples of the type of burial developed in Rome at the end of the thirteenth century. The church was built starting from 1237 on land that Pope Gregory IX had given to the Franciscans. The facade has a Romanesque portal with twisted columns; the interior has a Latin cross plan, with a square apse, and a trussed ceiling. The marvelous "Pietà" by Sebastiano del Piombo was made precisely to decorate one of the altars of the church.Today a copy is visible inside the structure, while it is possible to admire the original work of art at the Civic Museum of Viterbo.