National Geographic : 2006 Jul
A rivulet coming from the darkness flows down the rubble. Someone asks if it's dirty or clean. "It's very dirty," Luca says, eyeing the opening beyond, "but very important." T he cloaca, originally an open drain, was intentionally buried during the time of the Roman Republic, but most of what underlies Rome is there accidentally, buried by two mil lennia of sedimentation and urban growth. "Rome has been rising for 3,000 years," says Darius Arya, an archaeologist and director of the American Institute for Roman Culture. Much of Rome is situated in a floodplain, including the modern city center, known in antiquity as Campus Martius, at a bend of the Tiber River. Although the Romans put up levees, the city still flooded periodically, so they built upward, laying new structures and streets on earlier ones. "It was cost-effective, and it worked," Arya says. 96 NATIONAL GEOGRAPHIC . JULY 2006 "We see the Romans jacking their city up two meters at a time, raising themselves above the water but also burying their past." Today the city sits on layers of history 45 feet deep in places. But ironically, while the beguil ing truth of Rome is that you can dig a hole any where within the 12-mile ring of walls that once enclosed the ancient city and find something of interest, comparatively little of this buried city has been excavated. "I don't imagine more than 10 percent has been documented," Robert Coates-Stevens says. An archaeology fellow with the British School at Rome, Coates-Stevens has been trying for a decade to piece together the topography of ancient Rome. During the 1800s, the Roman Forum was dug out-work that continues-but most ancient structures are still trapped under the traffic-clogged streets and office buildings of the contemporary city. "It's a heady feeling,"