Fort Boyard
Mid-way between the Aix and Oléron islands, this symbol of the Charente-Maritime was built to defend the coastline and its islands.
Masterminded by Napoleon, construction took over 30 years, of which 20 were spent on the foundations alone. But developments in artillery outpaced construction, rendered the work immediately useless. Its renaissance came in 1989 when it was purchased by the General Council, and it has enjoyed a second career as an open air television studio and game show adventure playground.