A military bunker located near Saint-Quentin-en-Yvelines, France, believed to be part of France's nuclear deterrent infrastructure. The site is thought to be a command center or control bunker for France's nuclear arsenal, which is the fourth-largest in the world. France's nuclear capability is used to protect the country and, in its view, help protect Europe.
The bunker's exact purpose and layout are not publicly known, but it is likely to be a secure facility for managing France's nuclear warheads and defense systems.