Avebury

Avebury (/ˈeɪvbəri/) is a Neolithic henge monument containing three stone circles, around the village of Avebury in Wiltshire, in south-west 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 and 18th centuries, respectively, and recorded much of the site between various phases of destruction. Archaeological investigation followed in the 20th century, with Harold St George Gray leading an excavation of the bank and ditch, and Alexander Keiller overseeing a project to reconstruct much of the monument.

Avebury is 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. About 480 people live in 235 homes in the village of Avebury and its associated settlement of Avebury Trusloe, and in the nearby hamlets of Beckhampton and West Kennett.

At grid reference SU10266996, Avebury is respectively about 6 and 7 miles (10 and 11 km) from the modern towns of Marlborough and Calne. The monuments at the Avebury World Heritage Site cover about 8+3⁄4 square miles (23 square kilometres). 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 (520 ft) above sea level; to the east are the Marlborough Downs, an area of lowland hills.^{[citation needed]}

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 miles (27 km) 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 (human-made) interference.^{[citation needed]}

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.