Built in 1200 as the seat of the chief magistrate (podestà), this is the oldest of the palaces around Piazza Maggiore. The Voltone del Podestà — the great vaulted passage cutting through the building — has a peculiar acoustic quirk: stand in one corner and whisper into the stone and a friend in the diagonal corner can hear you clearly, while anyone in the middle hears nothing.
Each of the four corners of the vault holds a terracotta statue of one of Bologna's patron saints: Petronius, Procolus, Florian, and Dominic. The Renaissance brick facade was added in the late fifteenth century by the Bentivoglio family. Inside, the upper floor hosts temporary exhibitions.