Catacombe di Santa Domitilla

Lonely Planet review

Among Rome’s largest and oldest, these wonderful catacombs stretch for about 18km. They were established on the private burial ground of Flavia Domitilla, niece of the emperor Domitian and a member of the wealthy Flavian family. They contain Christian wall paintings and the haunting underground Chiesa di SS Nereus e Achilleus , a 4th-century church dedicated to two Roman soldiers martyred by Diocletian.