The 150-metre-long area was discovered during routine preventative excavations ahead of the widening of the A75 motorway, near Veyre-Monton, between Clermont-Ferrand and Issoire, in Puy-de-Dôme (Auvergne-Rhône-Alpes).

The findings were confirmed as prehistoric by archaeological research body l'Institut National de Recherches Archéologiques Préventives (INRAP).

In a press release, it said: “This is the first time that such structures, [standing stones known as] menhirs, have come to light in Auvergne, and more widely in the centre of France.”

INRAP has said that there appear to be few traces left among the stones to help with dating them precisely, but the institute is now planning a series of analyses.

Early estimates suggest that the findings could date back to the Neolithic era (New Stone Age) or the Bronze Age - from anywhere between 6,000 to 1,000 BC.

The stones measure 1m by 1.60m, and are “spread out across 150 metres across the excavation, and likely beyond it”, researchers said. They are in a north-south formation, and are in the style of “large, megalithic, Armorican monuments”.

In the same way as those found in Carnac (Morbihan), the monuments have “an impressive layout”, with the largest stones at the top of the slope towards the north, and the smallest, closer together and more towards the south.

One stone is more “sculpted”, and is “largely anthropomorphic”, researchers added.

The statement said: “This ‘statue’ is the only example [of its kind] known in the Auvergne. It has a rounded head, placed on rough shoulders, and shows two small breasts.”

The excavation also revealed a burial ground, with the remains of a tall man, which had been covered with a stone that was 14 metres long and 6.5 metres wide.

The statement continued: “In the same way as other monuments, such as Belz in the Morbihan, the menhirs of Veyre-Monton were taken down, to make them disappear from the countryside. They were pushed into large pits, sometimes damaged or covered in soil…[and] deliberately erased from the countryside.

“They were the object of iconoclastic acts; a sort of condemnation that may be linked to a change of community or of beliefs.”