The Carneddau Hengwm are a couple of quite large tumuli or Neolithic burial chambers that are about two and half miles inland from Llanaber off the A496 Meirionnydd coastal road between Barmouth and Harlech. They lie in an East to West alignment, about fifty yards apart and at an altitude of 900 feet.
The ‘Southern’ tumulus is much larger (approximately 150 feet in length and about nine feet high in places) and is in better condition. It has a collapsed Dolmen at the eastern end, and an intact burial chamber with a large capstone and lateral passage entering from the northern edge. Another chamber on the southern side with no capstone or apparent passage is visible. This tumulus seems to have two styles (dolmen and lateral passage) which might indicate that the tumulus was used over a long period of time. The tumulus is bisected by a stone wall at the eastern end.
It’s not easy to find the Carneddau Hengwm, because stones walls dividing the land render them inconspicuous to the eye. To get to them, turn at Egryn farm and follow the track up the hill, skirting the ravine and the brook. Try to continue due east.