More scary are the various Royal Observer Corps bunkers that are scattered across the UK.
They’re basically a single small room, and a toilet, and their purpose was to report on nuclear bombs going off over the UK (range, direction, estimated size of blast etc.).
Unlike the bigger bunkers, they were barely hardened, and only had enough food and water for a week or two at most. Their whole purpose was to observe the bombs going off, and after that, they, and their crews, were of no further use.
(It’s amusing to look at the difference in scale of an observation post:
verses a Titian II silo in the US:
