The Collegiata di San Lorenzo is the main church of Chiavenna, a solid Romanesque-Gothic building that stands at the heart of the old town. The church itself dates from the eleventh century, though it has been rebuilt and altered many times since. The present facade is Renaissance, and the bell tower is medieval.
The real reason to visit is the treasure it contains: a twelfth-century baptistery with an extraordinary carved stone font, and the Tesoro della Collegiata — a small museum of liturgical objects that includes the famous Pace di Chiavenna, a jewelled Gospel cover from the tenth century that is considered one of the masterpieces of medieval goldsmithing. The museum is small and often overlooked by casual visitors, which makes it more rewarding to those who find it.