I'm a little bit out on a limb in designating this place as an ancient mine/quarry (Emphasis on the 'quarry', as there don't seem to be any pits). It's never been excavated, and was listed as a IA settlement, it's marked on the OS as a field system.
But on the ground, there is a very visible seam of what I think is metal ore. Soft, shaley stuff with a greenish cast, and many greenish tinged pebbles in the stream. There are very visible remains of structures, in the form of rings and rows of pink granite boulders, The building(?) remains are right next to the stream, and surrounding it are what could well be earthwork banks, protecting the area with the shaley strata.
If these observations are considered in conjunction with the field system, I reckon there's a case to be made for this having been a mine in prehistory. And I'm sticking with that until I hear otherwise.
The fact that there's a strange saline well with alleged medicinal properties just adds to the texture of the place. The whopping great Victorian Hotel, complete with attendant octagenarian techo-accordian player, I'm not so sure of. The presence of the hotel has resulted in the covering of the well, which is a bit shan.
The moorland nearby is spooky in the dark, with distant glows of modern pink granite quarries, buzzing overhead cables, faint sounds of the M6 drift in and out of earshot as you move over the ground. Especially if you are lucky enough to catch a blood-red full moon rising over the horizon. I could have done without the midgies though.