This documentary film focuses on a site which has marked the landscape of the area around Arles, in France, for millennia: the Mount of Chords. The megalithic graves built all around the mountain and the great sanctuary, the Cave of Fairies, dug out at its summit, were created by architects of late Prehistory worthy of their successors of ancient or medieval times. Covered walkways and galleries tens of metres long, menhirs and dolmens: all these prehistoric monuments of the Mount of Chords are nowhere else to be found in the Mediterranean and rival the megalithic complexes in Brittany and elsewhere. But what was their function? Will the enigmatic Cave of Fairies finally reveal its secrets to the 21st-century archaeologists who have come looking for answers? A virtual reconstruction based on drawings by Jean-Claude Golvin concludes the film.