a. Cadw SAM No.=GM027
An oval cairn, 20.7m by 14.9m and 0.7m high. An "inner cairn" of more massive stones may represent an original wedge-shaped structure, at its N end several large slabs may have formed a forecourt arrangement, or have been connected with the expected chamber.
(source Os495card; SS48NW2)
RCAHMW AP945091/44, 46; 955111/51, 53
J.Wiles 01.07.2002
RCAHMW 1976, An Inventory of the Ancient Monuments in Glamorgan, Volume 1, Part 1. Site Number 32, Figure 5 and Plate 2.

b. Like the northern of this pair of chambers the site is greatly disturbed with a chamber located in a cairn of conglomerate boulders. Measuring 20.7m (N-S) by 14.9m (E-W) this the south cairn is approximately 0.7m high. A wedge-shaped structure is suggested by several large boulders, some earth fast, near the centre of the cairn. The precise location of the chamber is unknown. Five slabs at the northern end of the cairn, of which only two are upstanding, may be the remains of a crescentic court. It has been suggested that the concave edge of one central slab (0.5m thick) has resulted from the removal of part of it for a millstone. Chambered tombs are generally assigned to the Neolithic period. The greatly mutilated condition of both of the chambers on Rhossili Down makes comparison with other megalithic burial structures difficult but a similarity with the small tombs at Maros in Carmarthenshire and Garn Wen in Pembrokeshire has been noted. It has also been suggested that these two tombs could be Portal Dolmens (R.C.A.H.M. Vol I (1) p26). Neither has been excavated and given the disturbed condition of each site it is unlikely that any artefacts have been preserved.
John Latham RCAHMW 1 September 2015
(source: NT Report, E Plunkett Dillon)