Hi Lee.
I would be tempted to have a walk around with a metal detector ( if I had one )
If you could find where they used to dump their rubbish, might get a few goodies mate?
Had my Lurcher out years ago on some ground at the back of us, he was digging in a burrow,in the middle of a thicket, and I spotted a bottle neck poking out.
Came home for a spade and had a dig around, got some nice bottles, pot lid's, and clay bottles too, even some old medicine bottles, great result, and interesting too.
Look forward to the new pic's mate.
ATB.
Bill.