Ancient burial chamber
The structure is a tumulus (earth mound) covering a cairn (stone mound) covering a dolmen (stone burial chamber), which was built around 3500BC and has a diameter of 164ft (50m). To reach the burial chamber visitors must walk down a low, narrow 46ft (14m)-long passage whose walls are decorated with carved patterns and symbols such as axe heads, horned animals and swirls. At Winter Solstice, the sun shines down the passage and hits the back wall.
The 17-tonne stone slab acting as the ceiling of the rectangular burial chamber is covered with drawings of a bull and some other incomplete designs. Amazingly, in 1984 it was found to be part of the same stone that covers the Table des Marchand dolmen at the megalithic site in Locmariaquer at the western entrance to the Gulf of Morbihan; there you’ll also find the Grand Menhir Brisé, a 66ft (20m)-high standing stone – the largest ever found from Neolithic times – that is now on the floor in four sections.
In order to visit Gavrinis, you have to reserve a place on a guided tour, which take place from April to October; the island is a 15-minute boat ride from Larmor-Baden. The 1h30 tour starts with a talk about the Neolithic period and its buildings followed by a visit of the interior of the structure. In July and August, you can visit Gavrinis at lunchtime to explore the island at your own pace followed by a picnic on the beach (you’ll need to bring your own supplies).
In the area
Larmor-Baden itself is a small, unremarkable village whose main economic activity is oyster farming. Before or after visiting Gavrinis, take a walk around the mainland’s coastal paths or visit the Marais de Pen-En-Toul, a marsh nature reserve, which hosts around 40 species of migratory birds and 42 species of butterfly.