Cattedrale di Santa Maria Assunta e San Lorenzo
Building work on the Cathedral of Tortona started in 1574 and ended around the end of that century; while the façade was finished at the end of the 1800s by Nicolò Bruno. Inside, the church has a Latin cross form with three naves, the central one having a barrel vaulted ceiling, the side naves having crossed vaulting; the rectangular presbytery is decorated with paintings from the 16th and 17th centuries; the frescoes on the ceiling by Paolo Maggi were executed in the middle of the 1800s. The church is home to several important works of art including the The Fall Of St. Paul by Fiamminghino and The Martyrdom of St. Marziano attributed to the school of Camillo Procaccino and various paintings by Moncalvo. The most important treasures of the church are kept in the presbytery and include a huge 16th century cross and a silver urn containing the remains of San Marziano.