Object 7a "Granit"

Dimensions: 33m X 6,9m X 5,79m (only the bunker part)

There were 3 types of the "granit" bunker. One of them was a drive-thru version and the other two sealed on one side. All three had a winch on the ceiling to move around the heavy missiles.
This type of bunker was mainly used for storage of nuclear missiles. 

In estonia they can be seen:
Rohuneeme S-75 missile base;
Türisalu S-200 missile base ;
Maanteeküla S-75 missile base ;
Kallemäe S-75 missile base

in germany there is a fully restored bunker: Grossenhaini airfield

Source: Türisalu seniitraketibaasi tuumarakketide hoidla