Fort Boyard is a historic fortification located in the waters between the islands of Île d'Oléron and Île d'Aix in France. Built in the 19th century, it was designed to protect the Bordeaux harbor from naval attacks. The fort is known for its unique architecture, featuring a rectangular shape and thick stone walls, and it has been classified as a historical monument. Today, Fort Boyard is famous for being the setting of a popular television game show that shares its name. The show, which first aired in 1990, features contestants who face various physical and mental challenges to win keys and treasures, all while navigating the fort's intriguing environment.