This stone is situated on a track between Carn Kenidjack and Woon Gumpas Common.Formerly known as Crowze East. The inscription reads JAC-T-VENA but is now barely visible.
Craig Weatherhill in his book "Belerion" thinks that the inscription is probably Hic Jacit Vena (here lies Vena).
I know the OS is in many ways untrustworthy, but this stone appears on sheet 102 as an inscribed stone. Also local artist and writer Ian McNeil Cooke doesn't seem to have any doubts as to the antiquity of the stone.