Archaeological excavations of Didonne’s vanished castle in Charente-Maritime
Charente-Maritime: the monumental moats of Didonne’s vanished castle uncovered by archaeology
Over 6,475 m² in Saint-Georges-de-Didonne, Inrap has unearthed the defensive ditches and village of an 11th-century seigneurial castle lost since the Hundred Years' War, leaving only a place-name.
Editorial journal · Carte des Châteaux ·
In Saint-Georges-de-Didonne, Charente-Maritime, a team from the French National Institute for Preventive Archaeological Research (Inrap) has been excavating the remains of a centuries-old vanished seigneurial castle since 2026. On a 6,475 m² site atop a limestone hillock overlooking the marshy Riveau valley at the entrance to the Gironde estuary, archaeologists have uncovered the monumental moats of Didonne Castle and the village that developed around it. Free open days, with guided tours every hour, allowed the public to explore the site on 29 and 30 August 2026.
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Moats 15 metres wide and 6.50 metres deep
The defensive system uncovered consists of two concentric ditches. The inner moat, the most impressive, measures approximately 15 metres wide and at least 6.50 metres deep, reinforced by a rock-faced embankment at least 10 metres wide—a colossal structure for the time. The outer moat, also 15 metres wide but far shallower (2.70 metres), was dug into flatter terrain. Around these fortifications, archaeologists have also uncovered the remains of the village that grew up alongside the castle: storage pits for crops, post holes indicating wooden structures, an organised network of ditches, and at least two wells—all clues to the daily life of a community settled on the estuary’s edge.
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A major seigneurial hub dating back to the 11th century
Medieval texts confirm the existence of Didonne Castle as early as the 11th century. It occupied a prime strategic position as a major seigneurial hub, controlling access to the Gironde estuary and the surrounding coastal routes. Contrary to local legend, which attributed its destruction to an English attack in the 15th century, archaeologists now favour a slower process: a strategic downgrading after the end of the Hundred Years' War in 1453, followed by abandonment and gradual ruin. Until these excavations, only a place-name, 'Le Châta,' and subtle irregularities in the landscape hinted at the castle’s vanished presence—details only archaeology could truly interpret.
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A preventive excavation ahead of a social housing project
As is often the case in preventive archaeology, it was an urban development project that made this discovery possible. The excavation, scientifically led by Catherine Vacher for Inrap and supervised by the Nouvelle-Aquitaine Regional Department of Cultural Affairs, precedes a social housing project by the SA Noalis housing association. A first archaeological survey in 2012, covering a much larger 16,000 m² area, followed by an initial dig in 2013, had already identified the moats and medieval occupation on the slope leading to the Chenaumoine marsh. The 2026 campaign has expanded and refined these early findings before the site is permanently covered by future construction.
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