Tristan Island or the Île Tristan is located at the mouth of the Pouldavid Estuary off the French port of Douarnenez in south-western Brittany. It is only about 450 m long and 250 m wide but despite its small size, it has a rich history, especially since the Middle Ages when a priory was built there. In the 19th century, it became famous as the site of the first canning factory for sardines fished in the Bay of Douarnenez. It is also closely associated with Breton legends and the island of Ys. Now uninhabited, the island has become a nature reserve which is only accessible to tourists once or twice a year or by special arrangement with the local tourist office.