Belle-Ile is the largest island bretonnes.85 square kilometers with an average altitude of 40 meters cut by many small valleys.
The coast of the island undergoes erosion from the sea, resulting in a very cut side, consisting mainly of cliffs. Evidence of this rapid erosion, the island Lonègues, which extended to the Middle Ages the art of Foals, has now virtually disappeared under the water.
The northern tip of the island extends islet connected to the main base of sand where the sea at high tide creeps.
On the mainland coast opposite the two lead rias that led to the creation of the two main ports of the island : Le Palais and Sauzon.
On this front is the main beach of the island (the Great Sands).
The climate of Belle-Ile is very ocean and has a particularly important sunshine. Frosts are rare, it rains more often than on the mainland and the winters are mild (average minimum 9) which allows the Mediterranean plants such as palm, grapes, figs, to thrive in the sheltered valleys.
Discoveries of coins and tiles show that Belle-Ile was occupied during the Gallo-Roman times. The island was called Vindilis. In the fall of the Roman Empire, it was colonized by Brittany came of addition Channel.