Map - Avebury

Avebury is a Neolithic henge monument containing three stone circles, around the village of Avebury in Wiltshire, in southwest England. One of the best known prehistoric sites in Britain, it contains the largest megalithic stone circle in the world. It is both a tourist attraction and a place of religious importance to contemporary pagans.

Constructed over several hundred years in the third millennium BC, during the Neolithic, or New Stone Age, the monument comprises a large henge (a bank and a ditch) with a large outer stone circle and two separate smaller stone circles situated inside the centre of the monument. Its original purpose is unknown, although archaeologists believe that it was most likely used for some form of ritual or ceremony. The Avebury monument is a part of a larger prehistoric landscape containing several older monuments nearby, including West Kennet Long Barrow, Windmill Hill and Silbury Hill.

By the Iron Age, the site had been effectively abandoned, with some evidence of human activity on the site during the Roman period. During the Early Middle Ages, a village first began to be built around the monument, eventually extending into it. In the Late Medieval and Early Modern periods, local people destroyed many of the standing stones around the henge, both for religious and practical reasons. The antiquarians John Aubrey and William Stukeley took an interest in Avebury during the 17th century, and recorded much of the site before its destruction. Archaeological investigation followed in the 20th century, led primarily by Alexander Keiller, who oversaw a project which reconstructed much of the monument.

Avebury is owned and managed by the National Trust. It has been designated a Scheduled Ancient Monument, as well as a World Heritage Site, in the latter capacity being seen as a part of the wider prehistoric landscape of Wiltshire known as Stonehenge, Avebury and Associated Sites.

At, Avebury is respectively about 6 and 7 mi from the modern towns of Marlborough and Calne. The monuments at the Avebury World Heritage Site cover about 8.7 square miles. Avebury lies in an area of chalkland in the Upper Kennet Valley that forms the catchment for the River Kennet and supports local springs and seasonal watercourses. The monument stands slightly above the local landscape, sitting on a low chalk ridge 160 m above sea level; to the east are the Marlborough Downs, an area of lowland hills.

The site lies at the centre of a collection of Neolithic and early Bronze Age monuments and was inscribed as a World Heritage Site in a co-listing with the monuments at Stonehenge, 17 mi to the south, in 1986. It is now listed as part of the Stonehenge, Avebury and Associated Sites World Heritage Site. The monuments are preserved as part of a Neolithic and Bronze Age landscape for the information they provide regarding prehistoric people's relationship with the landscape.

Radiocarbon dating and analysis of pollen and occasionally insects in buried soils have shown that the environment of lowland Britain changed around 4250–4000 BC. During the Neolithic period, argillic (clayey) brownearths reigned in the landscape formed by the acidifying conditions of a closed woodland, becoming more chalky as a result of clearance and anthropogenic (man-made) interference.

The area was originally a mix of deep argillic brownearths on clay-rich areas along with calcareous (chalky) brownearths that were "predisposed" to transforming into grassland. The change to a grassland environment from damp, heavy soils and expanses of dense forest was mostly brought about by farmers, probably through the use of slash and burn techniques. Environmental factors may also have made a contribution. The long grassland area formed a dense vegetational mat which eventually led to the decalcification of the soil profile. In the Mesolithic period, woodland was dominated by alder, lime, elm, and oak. There is a major decline in pollen around 4500 BC, but an increase in grasses from 4500 BC to 3200 BC and the first occurrence of cereal pollen.

Pollen is poorly preserved in the chalky soils found around Avebury, so the best evidence for the state of local environment at any time in the past comes from the study of the deposition of snail shells. Different species of snail live in specific habitats, so the presence of a certain species indicates what the area was like at a particular time.

The available evidence suggests that in the early Neolithic, Avebury and the surrounding hills were covered in dense oak woodland, and as the Neolithic progressed, the woodland around Avebury and the nearby monuments receded and was replaced by grassland.