The photograph was taken by me, little old me in Plymouth whilst I were living in Penzance, the photo was taken via asking permission from the staff at The County Hall Nuclear Bunker in Truro.
This former Cold War Era Nuclear Bunker is still there, tho the blast doors were made from wood, so not exactly the best nor dafest place to be at if a Nuke went off.
This photo was recently shared with CyberHeritage too. So it might look familiar.
To the right is the original access / emergency exit tunnel although sadly this would be the only safe area if a bomb were to have dropped as each end has a blast proof door.
This is where the Raynet team in Truro meet, and no I wouldnt recommend them, more on that and why another time.