Visited Catesby in September (really nice tunnel) and great pics you have of it.
A bit surprised it has been fully sealed as the plans they have for it will take 5-10 years to even come to fruition. And that is before the bats have been brought into the equation !
Digging up an old post.... hold ya breath while the dust settles
Proper jealous you got to venture into the darkness. Yes it is being converted into a wind tunnel facility for the motor industry and a warehouse has now been built next to the southern portal. No work has begun inside the tunnel as they are still waiting for investment to the tune of £8m! Was there last Saturday to have a nosey (see my report) and there will be chances to venture through (legally) before it is fully converted.