A greater earthen bulwark believed to date from the Dark Ages. It originally ran from Chapel Porth to Trevaunance Cove.
Bolster is another word for bulge or pillow. Associating gigantic earthworks with gigantic people is quite common and constitutes "evidence" of the mound's unnaturalness. Six miles apart suggests the mounds were intervisible.In the time of giants in the Penwith area of Cornwall, there lived a particularly troublesome giant called Bolster, who was of such enormous stature that he could stand with one foot on Carn Brae, and the other on the beacon near St Agnes, a distance of 6 miles. Bolster himself was a terror to the surrounding countryside, stealing sheep and cattle from the ordinary Cornish people.
Sounds like a frightening, certainly an unpopular, activity was being carried out. Mining/smelting? Giants in folklore often owned piles of treasure.According to folklore, a giant called John of Gaunt lived on this ancient site. The giant had a rivalry with another local giant called Bolster.
The two would often engage in battle and throw boulders at each other. The many large erratics found in this area are supposed to be remnants of their battles.
Giants tossing hammers or throwing boulders across a valley has a very Megalithic ring to it.
From the photo Carn Brea looks far more desolate than the surrounding countryside. Its 'ramparts' have been dated to Early Neolithic, excavations here led to the coining of the somewhat vague term 'tor enclosure' presumably because no-one knew what a site like this, in use for millennia, was for. Could be a slag heap.