Fort Ste-Agnès

The drawbridged entrance to this huge underground fort sits at the top of Ste-Agnès village. The 2500-sq-metre defence was built between 1932 and 1938 as part of the 240km-long Maginot line, a series of fortifications intended to give France time to mobilise its army if attacked. The fort was maintained throughout the Cold War as a nuclear fallout shelter and the army only moved out in 1990.