Parking at the small pulling in area near Maen Llia standing stone I walked back down the road a short distance (south) until I came to the wooden stiles on the opposite side of the road. There are two stiles next to each other – climb over the small one. The ground is very bumpy and quite waterlogged.
Heading in a south western direction a short distance I think I spotted the remains of the Barrow, although I am not 100% certain. (It is very difficult to tell for sure in this terrain) I was able to make out a circular 'feature' about 8 metres across and less than 0.5 metres high. It had what appeared to be a small raised rim around the edge and the centre seemed to have sunken into the ground rather than dug into.
As I say, I cannot be 100% sure that I found the Barrow but what I saw was in the right area and there wasn't anything else nearby which looked 'Barrow like'.