The Vieux-château de l'île d'Yeu is a fortification on Île d'Yeu off the French Atlantic coast in the département of Vendée.Olivier IV de Clisson, a great builder of castles, undertook the work with the aim of protecting the islanders in the event of foreign invasion. The longest of these had been led by the famous English pirate, Robert Knolles, who managed to seize the castle in 1355 and occupied the island for 37 years. In 1381, Île d'Yeu was retaken during the reconquest of Poitou by Olivier V de Clisson.
During the Renaissance, Jean V de Rieux, master of the isle, erected towered walls around the castle. This type of construction was carried out by Italian engineers brought back from the Italian Wars by King Francis I. This protection proved effective in 1550 when several thousand Spanish soldiers attacked from the north. Held in check under the walls by the local garrison, they were forced to retreat by sea to the Iberian peninsula.
Wikipedia https://en.wikipedia.org/wiki/Vieux-château_de_l'Île_d'Yeu
Address France
Coordinates 46°41'58.02" N -2°22'7.519" E