It should survive nuclear explosion with a strength of 250 kt, hitting the vault at a speed of 300 m/s, at an incidence angle of 15 degrees. It is a concrete monolith with a circular floor plan (11 meters in diameter) and 1 meter thick walls.
There are two entrances on the surface - one civil and one military. Military entrance also contains decontamination and dosimetric rooms. Each of the entrances has a separate angled staircase, leading 10 meters below ground, to the first floor. Both staircases are turned against each other. There is also a lift inside of the vault with a load capacity of 250 kg.
Now the vault is under reconstruction, conducted by a group of enthusiasts. It is also available for the public, more information is available here (in Czech), and the Facebook group is here. The object is situated here.
Decontamination room, pressure chambers, emergency exits, air cleaning filters room, workroom
infirmary, operating room, warehouses
command room, low-voltage workroom, telephone exchange room
lodging for protected people, washroom, warehouse - party floor now :-)
lodging for protected people, washroom, warehouse - recently transformed to the museum of civil defense
lodging for protected people, washroom, diesel engine room, diesel engine control room, drinking water reservoir (14 m3)