Cley Hill

Cley Hill is a prominent hill to the west of Warminster in Wiltshire, England. Its summit has a commanding view of the Wiltshire / Somerset county boundary, at elevation. The land is in Corsley parish and is owned by the National Trust.
A area of chalk grassland at Cley Hill was notified as a biological Site of Special Scientific Interest in 1975. The land is managed by the National Trust, having been donated to the charity in 1954 by the 6th Marquess of Bath.
Archaeological features include a large univallate Iron Age hill fort, two bowl barrows and medieval strip lynchets. In 1812, local antiquarian Sir Richard Hoare attempted to excavate the mound at the top of the hill – leaving a hole which is still visible – but found that it had been looted by grave robbers.
The south west side of the hill was quarried significantly in the 19th century.

Mythology

There is a legend that the hill was formed by the devil, when he dropped a sack of earth with which he had planned to bury the town of Devizes. He had retrieved the earth from Somerset and was travelling to Devizes when he stopped to ask an old man the distance to the town. The man replied that he had been walking for years to reach Devizes, so the devil abandoned his plan.
In 1924, V.S. Manley wrote in his book, Folklore of the Warminster District: a supplement to the History of Warminster and the Official Guide:
Since the 1965 sighting of the "Warminster thing", Cley Hill has been a hotspot of UFO sightings and crop circles. Sightings were documented in 1967, 1996, 2001, 2005 and 2017.