The Palace stands in the namesake square and dates from the late thirteenth century. Its origin is controversial, but it is thought that it was built on the orders of the Neri della Greca family, on an old papal palace of 1157. The bell tower is from 1315, followed by the Captain of the People, which is called the Palace, there He placed the bell engraved with the symbols of the arts that is now currently on Torre del Moro. Among the main rooms, the Hall of the fifteenth century and the Hall that, in 1596, was sold at the Studium of the Faculty of Law, Theology and Logic. Restored in the late '80s, it is currently home to a Conference Center. In the basement, it was found a temple of the fifth century, an aqueduct and a Medieval cistern.