Here's a few pics that were taken of the nuclear bunker under my local town hall.
I found it after exploring the upper floors. This was my favorite part of the explore though, loved it.
The steps leading down to the bunker.
The thick re enforced concrete doors on all the entrances.
There were loads of corridors lined with thick steel doors, lots were still locked though.
The generator.
And control panel.
Parts of the water treatment facility.
Signs
Home Office communication equipment.
Massive store rooms. (maybe for food etc?)
Not sure what this was for, maybe something to do with the air filtration system?
The ducting seemed to lead to the outside.
Theres a morgue down here somewhere but sadly I didn't manage to find it, the place was huge.