Carnmore refers to this as Cnocan Nan Cobhar, though it's often termed 'Cnocan na Gobhar', a truly massive Long Cairn in the woodlands southeast of Kilmarie on Skye.
Indeed, the cairn is so massive that I at first missed it, walking past it thinking it was just the steep riverbank. It's the size of a house, but so heavily overgrown with rank vegetation, shrubs and bracken that it just blends into its surroundings. The giveaway is its summit, which reveals a number of boulders amongst the bracken.
This cairn can be difficult to find—I took two attempts. My starting point was the forestry gate at NG552177 on the road just northeast of Kilmarie. There is room to park and a kissing gate for access. After about 150 metres there is another gate to pass, then the path soon dips to a low point where it crosses a rushing stream, before climbing again.
Some 10-15 metres past this low point, on the right, a footpath heads due south towards the footbridge over the Kilmarie river (a 'No Camping - No Fires' notice conveniently marks the spot). Follow this path all the way to the bridge and turn left, where a footpath follows the riverbank towards the sea. Cnocan Nan Cobhar, which rises from the riverbank, is now in view, on your left, about 20 metres downstream.