1. A long cairn, or barrow, c.27m E-W by 11m and 1.0m high. At the E end, immediately behind a presumed forecourt area, is a megalithic structure composed of a 'cove' of three uprights, open to a presumed forecourt to the E, capped by a further megalith.
Human remains and coarse pottery have been noted.
(source OS 495 card; ST17SW3)
2. Chambered long cairn, Maesyfelin, also known as Gwal y Filiast, stands at about 70m above O.D., on ground falling gently to the N.W. near the head of the Waycock Valley. It is a conspicuous monument, which has been variously described and assessed since 1874, but never excavated. It is now in State Guardianship.
The remains comprise a rectangular chamber set in the E. end of a long mound, which is spread to about 27m E-W by 11m, with a maximum height of about 1m. The sides of the flat top seem parallel, about 7m apart, and the W. end tends to a square shape, suggesting that the whole monument may have resembled Tinkinswood in plan, but there is no trace of revetment. The burial chamber is also similar in position and general form, though more trapezoid in plan, and with a greater minimum internal height of 1.8m at the W. Both sides are formed by single massive slabs, which are earthfast only at their E ends; the end slab is triangular, leaning inwards and tapering almost to a point. All three slabs support the single great capstone, which is pitched slightly upwards to the E; all are of the same mudstone used at Tinkinswood, but were probably available locally. Human remains and coarse pottery were found in 1875 in the debris thrown out from the interior, which partly fills the hollow of the original forecourt in the E end of the mound.
RCAHMW, 1976, An Inventory of the Ancient Monuments in Glamorgan, Volume I, Cardiff: HMSO, page 39.
3. Severe erosion by cattle in 1992 lead to the exposure of sub-soil cairn material within the chamber and on the north side. This lead to the chance discovery, as surface finds, of a fragment of polished stone axe and several flint flakes - some retouched - by Toby Driver in 1992. These joined a fine leaf-shaped flint arrowhead, found independently in the same erosion feature, and placed in the National Museum Wales, Cardiff. The finds were published in Archaeologia Cambrensis, 1992 and constitute a significant addition to the poorly-recorded finds noted by Lukis in 1875. Following the discovery of these finds, conservation was carried out on the badly eroded tomb in the early 1990s with soil and turfs replaced to cover the exposed areas.
Driver, T. 1992. Shorter Notes: St Lythans Chambered Tomb, South Glamorgan. Archaeologia Cambrensis Vol. CXLI, 181-2
4. Excavations were undertaken by Dr caroline Pudney for Cadw with Archaeology Wales in 2011.
T. Driver, RCAHMW, 2012