Get yourself down there and take a look. The thing with exploring is access to places can constantly change or stay the same for years, so there's usually only one way to find out. Also once you get a few reports up people will be more likely to share info, invite you out, etc.
I would love explore some of the hidden depths around wigan n surrounding areas, theres a couple of places i would defo be up for but it not easy trying find a likeminded buddy to explore places that most likely be dark cold n wet,