Sentier de grande randonnée 340, Long-distance hiking trail in France

The GR340 is a long-distance footpath that follows the coast of Belle-Île-en-Mer as closely as possible, starting and finishing at Le Palais. An access path leaves from Bangor near the south coast and joins the main route at Port Kérel. The path is unpaved, with bare earth and grass, bordered by low shrubs, dry grasses and patches of purple flowers.

Belle-Île held strategic importance in French military history, with fortifications including the citadel at Le Palais designed by Vauban in the 17th century. These defensive structures were built to protect the island from invasion and to control maritime trade in the surrounding waters.

The trail starts and ends at Le Palais, the island's main port, and an access path from Bangor joins the main route at Port Kérel. In 2021 it was voted "GR préféré des Français" in a contest run by the Fédération française de la randonnée pédestre, which brought walkers to the island's coastal path.

Wear sturdy footwear and prepare for changing weather, as the coast is highly exposed to wind and fog can roll in quickly. There are no public toilets or drinking fountains along the trail, so carry enough water, food, and a bag for your trash to bring back to town.

In 2021 the GR 340 was voted "France's favourite long-distance path" in a competition run by the Fédération française de la randonnée pédestre. The route starts and finishes at Le Palais, and a connecting path leaves from Bangor near the south coast, joining the main itinerary at Port Kérel.