Skip the Line: Crypts and Roman Catacombs Small Group Walking Tour. Discover Rome's hidden delights and quirky sites on a 3.5-hour walking tour of the underground catacombs, Capuchin Crypt and the Basilica of San Clemente. The intriguing tour showcases the best of Rome's underground attractions, such as the crypt made from Capuchin monks' bones and the Domitilla Catacombs where early Christians worshiped in secret. Finish with a visit to Basilica of San Clemente to see a church like no other, and marvel at the centuries of history displayed through its architecture. Book now and Save 10%: Skip the Line: Crypts and Roman Catacombs Small Group Walking Tour.