Four meters beneath the shuffling feet of summer tourists, archaeologist Camille Colonna's team is excavating something the world has been waiting to see: Paris itself, layered like a time-capsule cake beneath Notre-Dame's forecourt.
When fire consumed the cathedral's spire in 2019, it devastated a symbol. When Paris rebuilt and reopened it in late 2024, the city faced an unexpected gift: a chance to landscape the bare square outside with trees and shade. But in a city where every layer of soil holds secrets, excavation precedes renovation. So a slice of forecourt became a open pit, ringed by barriers and crossed by wooden walkways, just steps from where tourists queue to climb the gargoyles above.
French media have called it the "dig of the century"—and the finds justify the hype. Lucie Altenburg, a conservator with Paris's archaeology unit, told the AP: "It's a rare opportunity for us to work on something that's tangibly going to make a difference to the history of Paris." Among hundreds of objects already recovered is a fourth-century coin stamped with the face of Emperor Constantine, and shards of medieval pottery painted with marks no expert has yet deciphered—mysteries waiting in plain sight.
The first traces appear just 50 centimeters down. But 4 meters lower, the deeper the team digs, the further back time stretches. Twenty centuries are stacked in that narrow slice of earth—roughly the height of two-and-a-half Napoleon Bonapartes standing on one another, as Colonna notes with the wit archaeologists develop working in graves. Some days they fill fifteen crates from ground that has lain untouched for decades.
This excavation reveals how Paris itself was built: layer upon layer, each age rising on the rubble of the last. At the cathedral's founding in 1163, the entire square was packed with medieval houses split by a single street. Digging down, Colonna's team reached the cellars of those houses—and therefore the centuries they represent. Below them lie Merovingian and Carolingian grain pits dating from the sixth to tenth centuries. Below those, darker and deeper, sits a dense Roman quarter from the fourth and fifth centuries. It is, quite literally, Rome at the bottom and Paris at the top.
The richest finds come from the foulest places: the deep pits beneath medieval houses that served as both latrines and rubbish dumps. Out of them emerge whole jugs and cups thrown away centuries ago, still intact, nestled among broken plates and animal bones. These ordinary vessels speak louder than any museum placard—someone used that cup, discarded it, and it waited in darkness for two thousand years to tell its story.
For visitors, the perspective is transformative. Emily Carter, a tourist from Manchester, told the AP: "You come to see the cathedral, then realize there's another city under your feet. That's almost more moving." Her insight captures what this dig makes visible: history is not something contained in museums. It is beneath every street, under every building, waiting. In Rome, the ground has risen 9 meters since the empire fell in the fifth century. When Athens built its metro for the 2004 Olympics, it sparked the largest excavation in Greek history and turned up tens of thousands of objects, now displayed in the stations themselves. Paris is no different. The city rises on its own past, and occasionally—when a cathedral burns and must be rebuilt—we get to look down and remember where we came from.