The oldest building is St. Peter’s Church, which has been used as a baptistery only since the late 13th century. Its shape and original dedication to the Holy Sepulchre make it one of the best-preserved examples of churches built in imitation of the Holy Sepulchre in Jerusalem.The baptistery is a brick and sandstone construction,typical of Monferrato;
The polygonal exterior plan is matched inside by a round plan consisting of a circular ambulatory and a central chamber determined by eight columns with cubic capitals with rounded corners. Access is through a door surmounted by a stone lunette decorated with interlaced ribbons.
The chapel of San Pietro in Consavia (also called the Valperga chapel after the patron, Prior Valperga) is adjacent to the baptistery and has a square plan. It dates from 1467.
The priory building, on the other hand, is preceded by two cloister wings on pointed arches resting on brick columns.
