Wow, this is a doozy. This is what my next shelter is going to look like. This is what you would call a hardened facility.
Bargain prices for what amounts to priceless construction. Apparently the British government has given up on even surviving WW3.
This is the exact same place that James Herbert set his post-nuclear atomic rat story DOMAIN, which is probably one of the most awesome post-apocalyptic books ever written. It's out of print but if you can get a copy I highly recommend it.