Catacombs of Domitilla

The Domitilla Catacombs on the Via Ardeatina form the largest of Rome's roughly sixty ancient catacombs, with about 17 kilometres of tunnels on four to five underground levels. They were laid out in the 2nd century on land belonging to the Christian noblewoman Flavia Domitilla and hold roughly 150,000 burials from the 1st to 4th centuries. Most striking is the direct neighbourhood of pagan and Christian iconography on the walls of the same gallery system - you can literally read the shift from antique religion to Christianity off the damp walls. Highlights include the cubiculum with the earliest known image of Christ as the Good Shepherd and the partially preserved underground basilica of Saints Nereus and Achilleus from the 4th century. The site is only accessible on guided tours, with a steady underground temperature of 14 degrees.