Probably constructed in the thirty-seventh century BC, during Britain's Early Neolithic period, today it survives in a partially reconstructed state.

Archaeologists have established that the monument was built by pastoralist communities shortly after the introduction of agriculture to Britain from continental Europe.

Built out of earth, local sarsen megaliths, and oolitic limestone imported from the Cotswolds, the long barrow consisted of a sub-rectangular earthen tumulus enclosed by kerb-stones.

Human bones were placed within the chamber, probably between 3670 and 3635 BC, representing a mixture of men, women, children and adults.

Between 3620 and 3240 BC it likely began to be re-used as a burial space, receiving both human and animal remains over a period of several centuries.

[5] This came about through contact with continental societies, although it is unclear to what extent this can be attributed to an influx of migrants or to indigenous Mesolithic Britons adopting agricultural technologies from the continent.

[12] These chambered tombs were built all along the Western European seaboard during the Early Neolithic, from south-eastern Spain up to southern Sweden, taking in most of the British Isles;[13] the architectural tradition was introduced to Britain from continental Europe in the first half of the fourth millennium BCE.

In each case initial utilisation of these places may have been fairly routine - for occupation, cultivation, grazing, or simply acting as nodal points in networks of paths.

But the body of stories, memories and associations these places held would have grown, some perhaps eventually being imbued with even mythical significance.

The archaeologists Joshua Pollard and Andrew Reynolds noted that by the mid-fourth millennium BC, the landscape around Avebury "was being stealthily transformed".

[17] Around thirty Early Neolithic long barrows are known from the uplands of northern Wiltshire, 17 of which were definitely or probably chambered, the others being unchambered.

[22] The presence of a kink in the flanking ditches, identified by resistivity survey in the 1960s, has led archaeologists to suggest that the long barrow may have been constructed in several phases.

[23] It is possible that the West Kennet Long Barrow was once a smaller movement that underwent expansion during the Early Neolithic period.

[26] Pollard and Reynolds suggested that "this was not a closed space, but one that facilitated ready access to mortuary remains and perhaps allowed a select few to gather periodically within the chambers in order to commune with the dead and ancestors.

[29] It is possible that it was chosen for inclusion in these monuments because of its associations with a far-off place, because of its aesthetic qualities, or because it was believed to contain the essence of supernatural beings.

[29] It is also possible that the builders of these monuments viewed the area of the Cotswolds as their ancestral homeland and that the use of oolitic limestone in these structures was a means of linking themselves to their past.

[38] It is possible that these human remains were collected together over a period of centuries outside the long barrow and only placed within it as part of a single event.

[40] In the late third millennium BC, a façade of three large sarsen stones was erected across the forecourt, blocking any further entrance to the chamber.

[12] Archaeologists have suggested that this is because Early Neolithic Britons adhered to an ancestor cult that venerated the spirits of the dead, believing that they could intercede with the forces of nature for the benefit of their living descendants.

[43] Early Neolithic people may have entered into the tombs—which doubled as temples or shrines—to perform rituals honouring the dead and requesting their assistance.

[45] The archaeologist Caroline Malone noted that the tombs would have served as landscape markers that conveyed information on "territory, political allegiance, ownership, and ancestors".

[48] The archaeologist Richard Bradley suggested that the construction of these monuments reflects an attempt to mark control and ownership over the land, showing a change in mindset brought about by the transition from the hunter-gatherer Mesolithic to the pastoralist Early Neolithic.

[54] However, the osteoarchaeologists Martin Smith and Megan Brickley noted that "demographic divisions" proved "hard to discern" among the skeletal material from West Kennet.

[59] Romano-British ritual activity is known from the broader area around the long barrow; several shafts were dug around the Shallow Head Springs near Silbury Hill in this period, into which a range of items were placed.

[62] Modern Pagan visitors have often left items, including tea lights, incense, flowers, fruit, and coins, in the long barrow,[65] often regarding these as offerings to "spirits" which they believe reside there.

[4] Circa 1814, the long barrow was reported on by the antiquarian Richard Hoare amid his descriptions of the archaeological sites in Wiltshire.

[68] In the autumn of 1859, John Thurnham carried out an excavation at West Kennet Long Barrow under the auspices of the Wiltshire Archaeological and Natural History Society.

[69] In excavating at West Kennet, Thurnham used patients from a mental asylum as labourers, presenting it as a form of occupational therapy for them.

[3] Darvill noted that Piggott and Atkinson's research was "rapidly published" and probably had "the greatest impact" of any Cotswold-Severn long barrow excavation in the mid-20th century.