Fleucharg Long Cairn has certainly been abused over the millennia, most probably in the last centuries. However, it is still a significant presence in the landscape worth visiting.
It was archaeologically excavated in 1937. Canmore ID 65063 (go to Links) states it "measures 150 ft NNE-SSW by 44 ft across the N end and 85 ft some 25 ft from the S end, and has a maximum height of 14 ft."
Of particular note was "a setting of three boulders, possibly part of a kerb" according to Canmore ID 65063.
There are also large voids in the cairn due to stone robbing.
It is identified as White Cairn in OS 1:50k maps.
I decided not to visit this one up close for reasons which may be obvious from the posted photo.
Anyway, it looks as if it's been mucked about a bit with field clearance and the best views are probably from where the photo was taken which is the road to the S.