It's been a while since I was in there. Is it the one where you have to climb over a fence and drop through a hole into the adit level? Once you're in there, there is no stoping, just a whole bunch of drives and crosscuts......There is a deep open shaft which has had forestry crap thrown down it......
I didn't get "the odd feeling" in there.
You can either cross the river or go for a mega walk through the forestry (which I did). Am I talking about the same place? Very dark blocky killas.
Edit: Down your way, where my mate and I both had an odd experience was Wheal Speed adit. I had the "we're not in here alone" feeling and kept quiet and then my mate piped up and said "bloody hell, blah blah, I could swear I heard something back there".....very very odd. I'm no kind of mystical vegan, but it was very very strange in the back of there. maaan.