Giant's Chair, Godolphin Hill.
On the S.W. slope of this hill is a very fine mass of rock, which has naturally assumed the shape of a chair. The back gradually slants off into an angle and surmounts the seat, which is much smoothed by attrition from the frequent use to which it has been put for sitting purposes by the neighbouring inhabitants. The seat is large enough to hold three persons, comfortably, and therefore we may reasonably suppose that the giant from whom it takes its name was three times as large as an ordinary human being. And he must have been at least as large as this, if, as the legend tells, he were able to hurl huge blocks of granite as far as Prospidnick, (where they formed the staple of the adjoining granite quarries,) a distance of close upon four miles, as the crow flies. He chose this rock as his chair to repose his wearied limbs after his exertions. The chair faces the hill so that there was no prospect to distract the giant's attention from sleep.
From Cornish Chairs by the Rev. S. Rundle, in v14 of the Journal of the Royal Institution of Cornwall (1900).
I can't see this marked on maps. But maybe it's noticeable if it's still there? The Bronze/Iron age people that lived here must have known it at least.