This week's dream: Exploring Rome's underground

The underground is "Roman archaeology's final frontier"

(Image credit: Filippo Monteforte / Getty Images)

published 18 June 2025

Much of ancient Rome, of course, "remains hidden under visitors' feet," said Tony Perrottet in Smithsonian. Visit the Pantheon or the Colosseum and you'll notice that the buildings' foundations sit far below current street levels. Plenty of what surrounded them lies under 30 feet of accumulated debris and new construction. That's what makes the underground "Roman archaeology's final frontier," inspiring two groups of amateur spelunkers to begin leading subterranean tours, opening up "a fascinating, multidimensional honeycomb of pagan shrines, public baths, hidden lakes, grand sewers, and Christian catacombs." Recently, I succumbed to "an obsession with the city's last hidden corners," starting on the day I visited an ancient underground aqueduct just outside the city.

Most of the 11 "superbly crafted" aqueducts that fed fresh water to Rome ran below grade, and I'd met that morning with several members of Sotterranei di Roma, or Undergrounds of Rome, to explore one. Donning hard hats and headlamps, we found an ancient maintenance hole in an overgrown field and descended by ladder into pitch darkness. A bat swooped past my head, and the walls were crawling with spiderlike crickets. "To some, this might be the stuff of nightmares." But I instantly wanted to see more. Surprisingly, "there are many other underground sites that are entirely accessible to travelers, if they know about them." I met up with a professor, Giuseppina Mattietti, who guides students via little-known museums or churches, such as the Crypta Balbi and the Basilica of San Clemente, to hidden worlds below the center city. Other sites "require some planning to visit," but Rome's Special Superintendence of Archaeology does grant requests.

The Sotterranei di Roma is headquartered in the Labyrinth of Rome, a 22-mile network of former quarry tunnels. One night, members guided me "deep into the dank maze" until we found a 20-foot ladder that rose to a hole in the stone ceiling cut by medieval tomb raiders to plunder Christian catacombs. We clambered up, and soon my headlamp illuminated shards of pottery, mosaics, and human remains, including a skull. I've visited impressive church catacombs, but "somehow, squatting in the darkness with my hands and knees covered in grime caught my imagination more." Tours of underground sites with Sotterranei di Roma (sotterraneidiroma.it) start at $17.