The Saint-Martin-de-Corléans Megalithic Area sits in a western suburb of Aosta, about two kilometres from the old Roman centre, and it pre-dates those Roman walls by several thousand years. The site was discovered during building work in 1969 and excavations revealed a complex of ritual use spanning from approximately 3500 BC to 1500 BC: ploughed votive furrows (among the earliest evidence of ritual ploughing in Europe), wooden posts, standing stones, and a remarkable series of anthropomorphic stelae — carved stone slabs depicting human figures with stylised faces, weapons, and ornaments.
The site is now enclosed within a purpose-built museum designed by the architect Diébédo Francis Kéré, opened in recent years, which protects the excavated area while allowing visitors to walk over and around the finds. The display is exceptionally clear and the scale of the sacred landscape — visible from above through the museum's viewing platforms — is genuinely impressive. For a city better known for Roman ruins, this prehistoric site represents a different and equally extraordinary chapter in the Aosta Valley's long human history.