North-West European lifestyles changed around 6000 BP, from the nomadic lives of the hunter-gatherer, to a settled life of agricultural farming: the Neolithic Revolution.

However, analysis of the human remains found at Parc Cwm long cairn show the people interred in the cromlech continued to be either hunter-gatherers or herders, rather than agricultural farmers.

[7] Historian John Davies has theorised that the story of Cantre'r Gwaelod's drowning, and tales in the Mabinogion of the water between Wales and Ireland being narrower and shallower, may be distant folk memories of that time.

[2] The warmer climate caused major changes to the flora and fauna of Great Britain, and encouraged the growth of dense forest that covered 80–90% of the island.

[9][10] John Davies notes that such a transformation cannot have been developed by the people living in North-West Europe independently, as neither the grain necessary for crops nor the animals suitable for domestication are indigenous to the area.

[12][13] They cleared the forests to establish pasture and to cultivate the land, developed new technologies such as ceramics and textile production, and used a similar tradition of long barrow construction that began in continental Europe during the 7th millennium BP – the free standing megalithic structures supporting a sloping capstone (known as dolmens), common across Atlantic Europe that were, according to John Davies, "the first substantial, permanent constructions of man".

[2][14] The cromlech at Parc le Breos Cwm is one of 120–30 sites identified as belonging to the category of long barrow tomb known as the Severn-Cotswold or Cotswold-Severn group.

[1][27] The cromlech consists of a north–south aligned long mound of locally obtained rocks and cobbles, mainly of limestone, revetted by two coursed, dry-stone kerbs of "a fine standard".

[32][35] The excavation revealed human bones that were "much broken and in no regular arrangement", animal remains ("deer and swine's teeth"), and sherds of "plain Western Neolithic pottery".

[28] Archaeologists Alasdair Whittle and Michael Wysocki note that such estimates were commonly based on the "numbers of skulls or mandibles", and recent analysis has shown the bones to be from at least 40 individuals.

[9] At Parc Cwm long cairn a variety of mortuary practices was evident and the deliberate ordering of skeletal parts noticeable.

5850 BP), although they are comparatively well preserved in the Black Mountains (Mynydd Du), Gower and the Vale of Glamorgan (Bro Morgannwg) where up to 50 individuals have been interred – men, women and children – in each cromlech.

[40] The skeletal remains of over 40 individuals were recovered from the cromlech at Parc le Breos Cwm, some of which showed evidence of weathering and of biting and gnawing by animals.

[1][39] Radiocarbon dated samples from the cromlech show the tomb was accessed by many generations over a period of 300–800 years, and that the human bones are the disarticulated remains (i.e., not complete skeletons) of at least 40 individuals: male and female adults, adolescents, children, and infants.

[42] Prior to the publication of Whittle and Wysocki's 1998 report, bones and teeth of the mortuary population of Parc Cwm long cairn were re-examined for indications of lifestyle and diet.

[41] In contrast, no such variation was noticeable in the remains found during excavations from other nearby sites, for example the Tinkinswood burial chamber, in the Vale of Glamorgan.

[39][42] Evidence obtained from stable isotope analysis shows plant foods, including cereals, formed only a small proportion of their dietary protein.

Dental analyses showed no sign of periods of decay or arrested development, even where there was "considerable wear", indicating a lifestyle that was not dependent on farming cereals.

[38] Whittle and Wysocki conclude, from the skeletal and dental analyses, that the lifestyles of the people who were to be interred in the cromlech either continued to be one of hunting and gathering or, more likely, a pastoral life of herding, rather than one of agrarian-based farming.

260–69", archaeologist Charles McBurney notes that "In the Post Glacial period the cave was much used by Mesolithic hunters"; a conclusion confirmed by John Campbell's excavation of 1977.

[45][46] A 1984 excavation by Aldhouse-Green revealed the earliest finds from the cave, two tanged points that may date to c. 28,000 BP, an interglacial period during the Late Pleistocene roughly contemporaneous with the Red Lady of Paviland.

Whittle and Wysocki note that this period of occupation may be "significant", with respect to Parc Cwm long cairn, as it is "broadly contemporary with the secondary use of the tomb".

[50][51] The Neolithic cromlech at Parc le Breos is about seven 1⁄2 miles (12 km) west south–west of Swansea, Wales, near the centre of Gower, midway between the villages of Llanrhidian and Bishopston.

[45] Parc Cwm long cairn lies on the floor of a dry, narrow, limestone gorge, at an elevation of about 50 feet (15 m) above sea level, less than 1+1⁄4 miles (2 km) from the south coast of Gower.

Established as an enclosed area of about 2,000 acres (810 ha) by John de Braose, Marcher Lord of Gower, in about 1221–32 CE, the park is now mainly farmland.

Facing the car park on the opposite side of the lane, a kissing gate allows wheelchair access to a level asphalt track running past the cromlech down the length of the gorge, passing within about 10 feet (3.0 m) of the cairn.