[1] The Hemlock Stone is an outcrop of New Red Sandstone, deposited more than 200 million years ago in the Triassic Period.

In 1908 the Ordnance Geological Survey (OGS) propounded that it was the result purely of natural differential erosion, particularly by ice in the Quaternary glaciation.

[2] In October 2015 with the University of Nottingham's Geospatial Institute undertook further study, as part of their "Three Stones Project".

In the Middle Ages it was claimed that the Devil threw the stone there from Castleton, Derbyshire, about 40 miles (64 km) away, because the ringing of church bells annoyed him.

From the Golden Jubilee celebration developed an annual free festival, the Hemlock Happening, that is held one day each June.