There are two decent cairns on Piles Hill and one less certain one. The southern cairn is an unusual bell cairn, with a definite raised perimeter of approximately 30m diameter surrounding it. The central mound is very low however and is exceeded by that of the smaller northern cairn. The less-certain cairn lies a few metres further to the north-east and is a low green mound with no visible structural stones. Sharp Tor cairn, with typical walker-excrescence, is an obvious monument on the skyline to the NNW from here.
There are two definite and one possible cairns on Piles Hill. Descriptions from Pastscape:
"(SX 65336084) Cairn
A cairn of rare type, consisting of a central mound, surrounded by a fairly level platform which is enclosed in an outer bank.
A bell-cairn of Wessex type situated at 387m. O.D. in a prominent position on Piles Hill. It is 29.0m. in overall diameter and comprises a platform 0.3m. high with the perimeter raised to a height of 0.5m. by the formation of a bank of stones incorporating a possible double row of orthostats although only the tops of these protrude. Centrally placed within the platform is a mound 17.0m. in diameter and 0.7m. high; it has suffered minor depredations with evidence of an excavation trench on the north side. The cairn could be described as a rimmed platform with central mound and is not common though examples occur in Cornwall on St. Breock Downs and Bodmin moor.
(SX 65326099) Cairn
A cairn 12.5m. in diameter and 1.1m. high situated on Piles Hill at about 385m. above O.D. There is an eccentric hollow in the mound, 4.0m. across and 1.0m. deep probably from excavation, but both the hollow and the mound are now mostly turf-covered.
(SX 65356104) Possible Cairn
At SX 65356104, 100m. north east of a cairn
(SX 66 SE 52), there is a circular mound measuring 8.5m. in overall diameter and 0.3m. high with a flat top 4.5m. across. It is not an obvious cairn since the mound appears to be of soil with no surface stone. There is however nothing to suggest that it is of modern origin and it is possibly a small bowl barrow, or perhaps an old peat mound."