It was back in the 1990's when I first went down it stuey before they capped it !
The adit level goes quite a distance both east and west. Some interesting stoping to the west that we got into before concerns about condition of ground and timberwork drove us out, by then we were into West Wheal Peevor !
Might have a survey someplace ...
If it can't be grown it has to be mined.