I believe that the bunker itself is at Watnall, Notts – a brief mention about the programme can be found in this link http://www.nottinghampost.com/Secret-bunker-given-stunning-TV-makeover/story-20609750-detail/story.html

Watnall was the HQ site that covered Duxford during the Batttle of Britain- Leigh-Mallory’s hideout, so its history is very important. Nice to see part of it being bought back to life. I’d love to go down into the underground parts, alas it is full of water.