A military bunker's a hardened shelter, often buried partly or fully underground, designed to protect the inhabitants from falling bombs or other attacks. They were used extensively in World War I, World War II, and the Cold War for weapons facilities, command and control centers, and storage facilities (for example, in the event of nuclear war). Articles for Bunker Types Air-raid shelter Blast shelter Flak tower Martello tower Observation post Line-Type Bunker Systems Atlantic Wall G… (More on Bunker)