Catacombs of Rome

The air changes first. A few steps below the street, the warmth of Rome falls away. A cool, still, slightly damp air settles on your skin. The sound of traffic is gone, and you can hear your own footsteps on packed earth. The walls on either side are close enough to touch. They are soft, brownish, and grainy, and they are lined with rows of empty rectangular openings, stacked one above another into the dark.

You are walking through a cemetery. The Catacombs of Rome are a network of underground burial galleries carved beneath the countryside that once surrounded the ancient city. Dozens of them are known. Most lie along the great Roman roads that led out of town, such as the Appian Way to the south and the Via Salaria to the north. Only a handful are open to visitors, and each one is a separate site with its own entrance, its own guides, and its own character.

Why are they out here, beyond the old city walls? Roman law did not allow the dead to be buried inside the city. So families buried their dead along the roads leading away from Rome. Pagan Romans built tombs and monuments above ground beside these roads. Christian and Jewish communities, from roughly the second century onward, began to dig downward instead. Land was expensive. Digging was cheap. And the rock beneath your feet made it possible.

That rock is called tufa — a volcanic stone formed from ash laid down by ancient eruptions in the hills around Rome. Tufa is soft enough to cut with simple hand tools. Yet it holds its shape well and tends to harden when exposed to air. Look closely at the walls and you may still see the marks of picks. Every metre of these corridors was cut by hand, by workers carrying the loose rubble up to the surface in baskets.

Those workers had a name: the fossores, from the Latin word for diggers. They were more than labourers. They planned the galleries, cut the graves, and often sold burial places to families. When one level filled up, they dug a new level below it. In some catacombs, the galleries descend through several layers, one stacked beneath another. The deeper you go, the later the corridors usually are, a quiet timeline written in stone.

Now look at those openings in the walls. These are loculi — simple shelf-like graves, cut just long enough for a body. Most people buried here were ordinary men, women, and children. A body was wrapped in cloth, placed in the niche, and the opening was sealed with tiles or a slab of marble. A name might be painted or carved on the seal. Sometimes, a family pressed a small object into the wet mortar — a coin, a shell, a piece of glass — so they could recognise the grave later.

Here is a detail many visitors miss. Look at the size of the niches. Some are surprisingly small. These were the graves of infants and young children, and in many galleries there are a great many of them. In the ancient world, child mortality was very high. Walking past these tiny openings, the catacombs stop feeling like an archaeological site. They feel like what they were — a place of grief, and of families doing their best for the people they loved.

Wealthier families could afford more. Watch for arched recesses called arcosolia, where a body lay under a carved arch. Look also for small rooms opening off the main corridor. These are cubicula, private family chambers. Many were plastered and painted. On their walls, early Christians developed a quiet language of images: a shepherd carrying a lamb on his shoulders, a dove holding an olive branch, an anchor, a fish. The fish was a coded sign. The Greek word for fish formed an acronym for a short statement of faith in Christ.

Now, a popular story says that early Christians hid down here from Roman persecution, holding secret services in the dark. It is a powerful image, and it appears in many novels and films. But historians largely treat it as a legend. The catacombs were known burial grounds, and the authorities knew where they were. Christians did gather here, but mostly to honour their dead and to mark the anniversaries of martyrs — not to live in hiding.

Those martyrs changed everything. As the tombs of saints and early popes became places of pilgrimage, the catacombs filled with visitors. In the Catacombs of Saint Callixtus on the Appian Way, there is a chamber known as the Crypt of the Popes, where several bishops of Rome from the third century were buried. In the fourth century, Pope Damasus restored many martyrs' tombs and added carefully lettered marble inscriptions to honour them. Some of these inscriptions survive today.

Then, slowly, the catacombs emptied. Burials moved above ground. Over the early Middle Ages, the relics of many saints were carried into churches inside the city, partly for safety. The pilgrims stopped coming. Entrances collapsed, and vegetation covered them. For centuries, most of this underground world was simply forgotten. In 1578, workers digging near the Via Salaria broke into a gallery by accident, and Rome began to remember what lay beneath its fields.

A scholar named Antonio Bosio spent years exploring these tunnels in the following decades. He has been called the Columbus of underground Rome. In the nineteenth century, the archaeologist Giovanni Battista de Rossi went further. He studied ancient texts and inscriptions and used them to locate and identify lost catacombs, including the tombs of the popes at Saint Callixtus. Today, the Christian catacombs are cared for by a commission of the Holy See, and visits normally take place with a guide.

Before you climb back up, pause for a moment in the corridor. Notice how quickly sound disappears here. Notice the cool air, the faint smell of earth and old stone, the long rows of empty niches. The bodies are long gone, but the names, the symbols, and the marks of the diggers remain. When you step out into the light and the warmth of the Roman road again, look at the fields and the pines around you. Somewhere beneath them, the galleries still run on in the dark.