Doomsday bunker complex the size of a city, back up plan for mankind
Bunkers were used by the Army in 1942 and built with reinforced concrete to withstand a 500,000-ton blast.
TAGS : the doomsday bunker complex the size of a city, back up plan for mankind, the city-sized doomsday bunker complex, house 10,000 people is being hailed as the back up plan for mankind, ifairer
