There is a robbed out cairn on the summit of Cairnharrow. It is roughly circular, measuring c. 12m in diameter and 1.3m in height according to Canmore ID 90588 (go to Links). There is a modern stone cairn in the centre of Cairnharrow Cairn, presumably constructed from stones removed from the surface of the cairn. The dry stane dyke S of the cairn could also account for the destruction of the cairn. The resulting turf footprint is covered by rough grass with a circular depression in the N Arc.
Cairnharrow is c. 3 miles E of Creetown. Creetown Summit Cairn is easily visited via Cambret Hill. Take the R turn 100 yards before the Gem Rock Museum in Creetown signposted for Glenquicken Farm Trout Fishery. After c. 2.5 miles there is a lay-by opposite Glenquicken Stone Circle on the R side. Continue E for c. 1.1 miles to the access track to Cambret Hill mast. There is a lay-by at NX 52645 57987 0.5 miles up the track, just below the Cambret Hill mast. I have plotted a 1.25 mile route S to Cairnharrow Summit Cairn via 3 Cairns, 1 Stone Circle, 1 Cup and Ring Marked Stone and 1 Modern Worked Stone on https://explore.osmaps.com/route/12211781/cambret-hill-and-cairharrow-cairns?lat=54.887958&lon=-4.308434&zoom=13.2069&overlays=&style=Standard&type=2d.
According to the RCAHMS record, a cairn crowns the summit of this mountain. It's covered in grass and has a bit of a hazy outline, and has a modern marker cairn added on the top.
The New Statistical Account of Scotland says:
The most remarkable hill [of this parish] is Cairnharrow, lying partly in Anwoth and partly in Kirkmabrec, the height of which is 1100 feet. The soil on it is of a mossy kind, covered with heath intermixed with graass, and not much encumbered with rock. Cairnharrow is the highest eminence within twent miles, with the exception of Cairnsmore in the parish of Minnigaff; and its summit commands one of the most interesting and extensive views imaginable, -- not merely the adjacent country and bays of Wigton and Fleet, but the Isle of Man, part of Cumberland, and the high land on the coast of Ireland.