Since February 2026, archaeologists from the City of Paris and Inrap have been excavating two courtyards of the Hôtel-Dieu, a historic building in the heart of the city. This summer, they uncovered a wall made of stone and wood, preserved over approximately 20 meters. The structure, nearly the length of a tennis court, is located just a few steps from Notre-Dame. Its surface shows signs of a violent fire, and it could be the first material trace of the rampart of the Gallic Lutetia, an ancient settlement that later became Paris. The discovery was made in July 2026, beneath the Hôtel-Dieu, and includes burn marks and a Gallic spear found at its base, suggesting a context of Gallic destruction. Carbon-14 dating places the wall between 200 and 10 BCE, covering the year 52 BCE, which marks the Roman conquest of the region by Julius Caesar. The excavation is being carried out by the City of Paris Archaeological Service (DHAAP) in collaboration with Inrap, under the supervision of the DRAC, with David Couturier leading the operations. The structure was revealed to the press on Wednesday. The wall combines stone blocks and wooden pieces placed horizontally, a technique typical of Gallic fortifications at the end of the Iron Age. Behind the wall, archaeologists found an artificial platform of sand and gravel nearly 2 meters thick. This material was brought from outside and deliberately deposited. Such a mass, adjacent to a stone and wooden wall, resembles a defensive device, leading to the hypothesis that it might be a rampart. However, the exact function of the structure remains to be determined. Radiocarbon dating provides an initial timeframe for the wooden elements of the wall, placing them between 200 and 10 BCE. This range covers 190 years, similar to the span from 1836 to today if one were to date an object from the 19th century. It includes 52 BCE, the year of the region's conquest by Caesar, but it is not yet clear on which side of that date the wall was built. In front of the wall, archaeologists found the remains of a wooden building destroyed by an intense fire. The surface itself is blackened, and charred seeds were found nearby. A Gallic spear at the base of the wall suggests a possible episode of combat or destruction. In The Gallic Wars, Caesar describes Lutetia as being on an island in the Seine. He notes that in 52 BCE, the Parisii set fire to their oppidum, or fortified settlement, before Roman troops arrived. However, no Gallic remains had previously been found on the Île de la Cité to confirm this account. This has led some to suggest that Lutetia was located in Nanterre instead. The mayor of Paris, Emmanuel Grégoire, called the discovery "vertiginous" and said it might provide an origin "probably" found for the city. However, this statement is more political than scientific. The archaeologists remain cautious, emphasizing that the wall's exact purpose and the time it was built and burned are still unknown. The excavation will continue for several months, with further analysis of broken amphorae, a spear tip, a coin, and the layers of sand and gravel found near the wall. David Couturier said, "We cannot exclude new surprises." For now, the only certainty is that beneath one courtyard of the Hôtel-Dieu, a stone and wooden wall, burned and dated between 200 and 10 BCE, awaits to reveal its place in the history of Lutetia.