Nyköping Civil Defence Bunker is situated in a grassy hillside on the outskirts of the town. A entry passage leads downhill through native rock to an excavated cavern large enough for the two storey structure within.
The structure is built without touching the outside walls - both to reduce vibration shocks and to protect from moisture ingress. Entry is through an air lock and decontamination facilities. There are control rooms, communications racks, dormitories and the standby generator was in working condition when visited in 2006 although the site had not been in active use since the mid 1990s.
Access hatches in most rooms gave both the ability to check the condition of the surrounding bedrock and to function as emergency exits.