Destroyed (1879) cliff castle. Info from Pastscape:
Borlase claims there were traces of a cliff castle at Cape Cornwall the defences of which had been partly effaced by agricultural improvements. There works disturbed a cairn in which a large urn was found and which is said to have been re-interred in the ditch of the cliff castle. Part of this ditch was cleared by Borlase and on the bottom, at a depth of 8 ft. pottery, flints and charcoal were found, also a small covered cist which was empty.
No certain traces of the promontory fort could be seen but across the lowest and narrowest portion of the neck joining it to the mainland there is a very vague and unsurveyable ridge visible in the pasture field. It is very ploughed down and may be natural but its position agrees with Borlase's description and is an obvious site for defending the promontory. The ridge best viewed from the north, extends from SW 3522 3179 to SW 3525 3184. A 25" survey has been made.