Home to about 40 Benedictine monks, this abbey – shut down during the Revolution and reopened in 1944 – is known for its Romanesque basilica, whose 11th-century crypt houses the relics of St Benedict (480–547). Visitors are welcome to attend prayers (held six times a day), chanted by the monks in haunting Gregorian monophony – a spiritual experience even if you're not religious. From about December to Easter, all services (except for Sunday Mass) are held in the crypt.