In reply to afx22:
I just looked at my logbook and it was a November when I was there, I did manage a few problems though it was mainly to clean and dig the top off.
I was told it was like a jungle before and a serious effort for the lad who found it to gain access. It's located about 10m set back from the river, look out for a clearing, there's bound to be shrubbery but there shouldn't be any big trees.
This is filmed from the location: