What's the noun for bunkers? Here's the word you're looking for.
bunker
(military) A hardened shelter, often buried partly or fully underground, designed to protect the inhabitants from falling bombs or other attacks.
(Britain) A large container or bin for storing coal, often built outside in the yard of a house. Now rare, as different types of fuels and energy sources are being used.
(nautical) A container for storing coal or fuel oil for a ship's engine. [Also, by extension] the quantity of fuel needed to replenish that container.
(golf) A sand-filled hollow on a golf course.
(paintball) An obstacle used to block an opposing player's view and field of fire.
(Scotland) A sort of chest or box, as in a window, the lid of which serves for a seat.