|The semi deserted hamlet at Bosporthennis - image by Carl Weaver [CC-BY-SA-2.0 (www.creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons|
...In Bosprenis Croft there was a very large colt or cromlech. It is said to have been fifteen feet square, and not more than one foot thick in any part. This was broken in two parts some years since, and taken to Penzance to form the beds for two ovens."
Map - Bosporthennis Coit (site of a large broken Cromlech - possibly the one mentioned)