Just metres below the queues of tourists braving the summer heat outside Notre-Dame Cathedral in Paris, a team of archaeologists is unearthing layers of history that stretch back nearly two millennia. The excavation, now reaching four metres deep, has revealed remnants of Roman Lutetia, Merovingian and Carolingian structures, and medieval Paris—all beneath the forecourt that will soon be transformed into a greener, cooler public space.
From Roman Lutetia to Medieval Paris
The dig began as part of a broader redevelopment plan for the square in front of the cathedral, which reopened in late 2024 after the devastating 2019 fire. Parisian authorities aim to reshape the area into a climate-resilient plaza, planting around 160 trees and adding shading features to combat rising urban temperatures. But before construction can start, French law requires a thorough archaeological survey—a routine precaution in a city where the past lies just beneath the asphalt.
“It’s a rare opportunity for us to work on something that’s tangibly going to make a difference to the history of Paris,” said Lucie Altenburg, a conservator with the Paris archaeology unit. The team has turned a section of the forecourt into an open excavation site, where traces of earlier eras appear as shallow as 50 centimetres below the surface. On productive days, they recover up to 15 crates of artefacts.
Among the finds are jugs, cups, and ceramics—some intact after centuries underground. “It’s rare to find complete ceramics,” noted archaeologist Valentine Breloux, explaining that the soft waste deposits have miraculously preserved whole vessels. A fourth-century coin bearing the face of Roman emperor Constantine has helped date the layers, while some pottery fragments show faint reddish markings whose meaning remains undeciphered.
The excavation has also uncovered fragments of a Roman column, evidence of the dense urban quarter that once stood here when the city was known as Lutetia. Above those Roman foundations lie medieval remains, including structures from the Merovingian and Carolingian periods, offering a vertical timeline of Parisian evolution.
For now, archaeologists hope to dig even deeper—beyond the Roman layers—in search of traces of the Gauls, the area’s earliest known inhabitants. The project is expected to be largely completed by 2028.
“It makes Notre Dame feel alive again,” said Emily Carter, a 34-year-old tourist from Manchester waiting in line with her two children. “You come to see the cathedral, then realize there’s another city under your feet. That’s almost more moving.”
Similar urban archaeology projects across Europe, such as the restoration of Milan's Galleria bull mosaic after centuries of wear from luck-seekers, highlight how construction often doubles as a window into the continent's layered past. Milan Restores Galleria Bull Mosaic After Centuries of Luck-Seekers' Wear.
The Notre-Dame excavation also echoes broader European efforts to adapt historic spaces to climate change, a challenge that cities from London to Lisbon are grappling with. London's Natural History Museum Dives Into Jurassic Oceans and Climate Lessons.
