Île-d'Arz (French pronunciation: [il daʁ]; Breton: An Arzh, pronounced [ãnars]) is an archipelago of nine islands and a commune in the Morbihan department, Brittany,[3] northwestern France, only 6 kilometres (3.7 miles) to the southwest of Vannes.

There is one bus service between the town and the port, three passenger boats which travel between the archipelago and Vannes and one merchandise ship which follows the same trajectory The main island has been inhabited since 4000 BC.

In 1008, Geoffrey I, Duke of Brittany, died and gave by his will the southern half of the island of Arz to the Abbey of St Gildas de Rhuys.

Construction of the priory of Notre Dame was started in 1034 by monks seconded from the Abbey of St Gildas de Rhuys.

The priory of Notre Dame was acquired and renovated by the municipality in 1970 and now serves as both the town hall and school for the island.

In 1032, Alain III, the son of Geoffroy 1st, decided to create his own priory under the governance of the Abbey of St Georges of Rennes.

The owners of Kernoel from the 11th to the 14th centuries are unknown, but it seems that the abbey of Saint Georges de Rennes sold one of the main building along with some land to a nearby lord.

During the post revolutionary terror years, Jean-Vincent struggled to protect the Ile d'Arz from numerous attacks from the Chouans who were sailing from mainland.

The Berno Mill was built under the religious community Saint Gildas de Rhuys who exerted its power in the southern part of the main island.

On 28 November 1994, Jean Bulot, an Iledarais, created an association in order to restore the mill to its previous majestic state.