This site is of disputed antiquity. If you have any information that could help clarify this site's authenticity, please post below or leave a post in the forum.
In the Peak District for the weekend, we were trundling down the B6049 past the hamlet of Blackwell towards Miller's Dale. I had been testing the patience of my future in-laws with talk of antiquities in the area so when a human-sized box shape of upright flat stones came into view alongside, there was a shout of "stones!" from the back seat. Ah, how pleasing a sound that is. Stopped off for some snaps on the way back up. This site is not marked on Ordnance Survey nor scheduled but is very convincingly a megalithic chamber similar to nearby Five Wells (but one not two chambers). One of the stones has a small circular hole through it, maybe 2 inches diameter.
I'd regard this as "of disputed antiquity" until we know any better.