Fort Boyard is a fortification on a shoal originally formed by a sandbank which can be seen at low tide, and is located in Pertuis d'Antioche between Île d'Aix to the east, Île d'Oléron to the west, Île Madame to the south and Île de Ré to the north. It belongs to the Charente archipelago and features on the land register of the Île d'Aix municipality, in the department of Charente-Maritime.
While the construction of a defensive system was planned as early as the 17th century, the project was only realised in the 19th century.
Built in order to protect the harbour, the mouth of the Charente, the port and above all Rochefort’s large arsenal, it was converted into a prison just a few years after its completion. Now the building is mainly known for the TV game show of the same name.
Fort Boyard is an integral part of Rochefort’s Maritime Arsenal, which stretches all along the Charente estuary.