Yeah I thought that too. The lower half of the quarry which included the lake was sold off for millions a few years ago.
Now the whole area is fenced off, there are CCTV camera’s mounted on huge poles, razor wire and huge “Private keep out” signs everywhere. It’s bloody grim, like something out of George Orwell 1984! The word is some mega rich guy who owns a scrap yard, Hills Motors I think is building some huge pile in this estate. There’s even some “security lodge” on the entrance to the quarry. The filthy rich obviously want to flush us “oiks” out!
Bloody grim I tell thee! I’d avoid this area if I was you. Any other areas you like to retrace let me know.