Rome's most atmospheric ancient monument, the 2,300-year-old Appian Way stretches south from the city walls through open countryside, flanked by ancient tombs, umbrella pines, and catacombs. The first stretch (about 10 km) is best explored on a hired bicycle — the road is closed to cars on Sundays — passing the Tomb of Cecilia Metella, the Circus of Maxentius, and countless anonymous funerary monuments that once lined the road in an unbroken procession.
The San Callisto Catacombs and San Sebastiano Catacombs are the most accessible along the route, both offering guided underground tours that pass through kilometers of early Christian burial galleries cut from the volcanic tufa. The park office on Via Appia Antica provides maps and rents bicycles.