The architectural complex of San Lorenzo (VIII-IX Century) is considered one of the most important of Piedmont. The church, with a single arched ceiling room, it has a rectangular apse and two chapels, destined to house sarcophagus, which stick out on the side as a transept. Only during a subsequent period the left arm of the transept and the baptistery were connected using a hallway where two other sarcophaguses are buried. Many frescos, which can be dated to the era the church was built in up to the end of the XV Century, are spread throughout the inside of the church, among them the cycle of frescos of the Avogadro chapel, in the right wing of the transept. The baptistry, with an octagonal centre plan, internally is divided into eight recesses with one of them connected to a square apse on the East with a small bell tower, added in a later era, at the centre of the vault.