I've been in the tunnels under Wollaton hall twice and whilst there are "tunnels" (theyre long tunnel shaped rooms, which were actually built and used for cold storage. At the very end of the 2 tunnels is a sandstone well which was used for drinking water (having been cleaned by the sandstone) and was used as a swimming pool by Sir Francis Willoughby.
If you wanted anymore proof, the Americans and British used Wollaton during WW2 while amassing troops for D-day. They buried all the tents/housing/infrastructure etc etc on the grounds. About 10-15 years ago they planned to do some archaeology and dig some of it up, but they ran into asbestos (used to build the makeshift buildings) almost immediately and stopped.
I've got the pictured somehere of all of this.
Outside the mail entrance are some wooded beams on the floor (punk.lung.thick what 3 words), we were told by the woman taking us on the tour that this was from where a bus full of school kids drove up to the front of the hall and the road fell into the cave/tunnel