It is the oldest church in the city, founded between the end of the 11th and the beginning of the 12th century, probably at the behest of Matilde di Canossa. Inspired by the Church of the Holy Sepulcher in Jerusalem and dedicated to San Lorenzo (Roman martyr of the 3rd century), the rotunda has a central plan, with a gallery above. An ambulatory precedes and surrounds the nave, characterized by eight columns and a small apse.