Visited on a grey Easter Sunday (12.4.09) after walking from Stroud via Bisley. Using Baza's directions, the stones are quite easy to find and at this time of year the vegetation is only just starting to grow up - the stones can currently be seen from the lane.
There is little to be seen apart from the two upright slabs, covered in moss and positioned about 6 inches apart, on an east-west axis. From the east it is just about possible (by squinting/wishful thinking) to see what may be the remains of a low mound around the stones, but don't hold me to that.
As the stones are placed so close together it is difficult to know what part of what kind of structure they formed.
A brief note on access. The stones are right next to the lane, in a gated (unlocked) field. The lane itself is metalled up to a hundred yards or so to the west of the site, after which it becomes a rough, stoney track. Rather oddly, as the track doesn't seem to go anywhere, I saw two cars driving along it while I was there, one in each direction! It appears possible to park at the end of the metalled section and still leave room for other vehicles to pass. It's then a short stroll along the lane to the field gate.
The monument is placed high up on the Cotswolds, with the hilltop being to the west - the spire of Bisley church is visible due west (which apparently was used as a landmark by bombers in WW2, due to its high situation). To the east the ground slopes away down to Holy Brook.
Worth a quick poke about in the undergrowth if you're in the area.
I have been looking for this for a few years. In the end I had to ask Baza and I finally found it. A little underwhelming but profoundly sad. I cleared the growth around the stone otherwise it is invisible.
Very little remains of this long barrow, which was nearly completely destroyed in the 19th century AD.
All that's visibly left to see are two parallel slabs, set into the ground 6ins apart, and rising maybe 2ft above the ground, presumably part of a burial chamber.
They're not easy to find, despite standing barely ten feet from Hayhedge Lane, a minor road running from the village of Bisley, one mile away.
I entered into a field on the northern side of the road through a metal gate and walked westward to the corner of the field where they stand in the undergrowth.
"Men have had the terrifying experience of seeing headless human beings [here] which have vanished."
(Thank god they vanished, eh. Mentioned in Trans Brist Glouc Arch Soc 1931.)
Also, a look at the map shows that the stones are in 'Battlescombe' - you can't help speculating that they might be caught up in a story about people (or giants?) killed in battle - many megaliths are said to be such graves. Maybe if you live locally you know more??