Visited 25th May 2003: This site got me more excited than Capel Garmon. What a great place! Everyone else stayed in the car and I pegged it off to take a close look at the stones. What remains appears to be a collapsed chamber, and the ploughed down remains of the barrow mound to the east of it. The views from up here are very dramatic, especially looking west towards the mountains. This must have been quite a place!
I didn't have much time at Maen Pebyll because the light was fading and I'd set my heart on visiting the Gwytherin Stones before we set of home. Well worth a visit though, if you don't mind slumbering megaliths.
If you stand on the remains of the mound and face toward the ruined chamber there's a tiny sleeping goddess hill away away on the far horizon. We almost missed this but it went on to inspire the spaceship choir-a-thon 'Distant Ma She Dig Maen Pebyll'.
There is certainly remnants of a barrow on this site, though it is in a poor state of decay. There has been a debate whether this is actually the remnants of a standing stone or a barrow, but having visited the site recently am quite sure this was once a covered burial chamber, similar to many in the Conway valley area. All that remains are three large stones, probably way too heavy to remove, as must have been done to the rest of the mound. The floor is littered with fist sized rocks, way too small to be of any use, so is a small enbankment on one side of the mound. the site is in poor condition, and located near a farm track, right at the edge of a field, it is not sign posted, but clearly marked on the outdoor leisure map as a long barrow.
Visit and judge for yourself.