You don't have to have a strong religious faith to appreciate the tranquil atmosphere of Cambrai Cathedral. Inquire when the next mass is scheduled or when it's open for general viewing.
This principal church is often on the itineraries of visitors to Cambrai. But Cambrai Cathedral isn't the only drawcard here. Aristide-Briand Square, Musee de Cambrai, and German Cemetery on the Solesmes Road are some other interesting sights nearby.