Avebury

 Avebury is the site of an ancient monument consisting of a large henge, several stone circles, stone avenues and barrows, surrounding the village of Avebury in the English county of Wiltshire. It is one of the finest and largest Neolithic monuments in Europe, about 5,000 years old. Although older than the megalithic stages of Stonehenge 32 kilometres (20 mi) to the south, the two monuments are broadly contemporary overall. Avebury is roughly midway between the towns of Marlborough and Calne, just off the main A4 road on the northbound A4361 towards Wroughton. Avebury is a Scheduled Ancient Monument, a World Heritage Site, and a National Trust property.

Location and environment

Avebury is respectively about 6 and 7 mi (10 and 11 km) from the modern towns of Marlborough and Calne. Avebury lies in an area of chalkland in the Upper Kennet Valley, at the western end of the Berkshire Downs, which 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. 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 (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 in buried soils have shown that the environment of lowland Britain changed around 4,250–4,000 BC. 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. 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 point in 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.

Before the henge

The history of the site before the construction of the henge is uncertain, because little datable evidence has emerged from modern archaeological excavations. Evidence of activity in the region before the 4th millennium BC is limited, suggesting that there was little occupation. Stray finds of flints at Avebury, dated between 7,000 and 4,000 BC, indicate that the site was visited in the late Mesolithic period by hunter-gatherers. A collection of flints found 300 m (980 ft) to the west of Avebury has been identified as a flint-working site occupied over several weeks. Despite minimal activity at early times, Avebury's later rise to importance follows a trend that is also seen at Stonehenge in Wiltshire and Hambledon Hill in Dorset. Another possible parallel with Stonehenge is the presence of a posthole, similar in shape to one at Stonehenge, near Avebury's southern entrance. Although this has not been dated, archaeologists Mark Gillings and Joshua Pollard believe that the position of the posthole, which is incongruous with the rest of the henge, indicates it probably dates to a pre-henge phase.

In the 4th millennium BC, around the start of the Neolithic period in Britain, British society underwent radical changes. These coincided with the introduction to the island of domesticated species of animals and plants, as well as a changing material culture that included pottery. These developments allowed hunter-gatherers to settle down and produce their own food. As agriculture spread, people cleared land. At the same time, they also erected the first monuments to be seen in the local landscape, an activity interpreted as evidence of a change in the way people viewed their place in the world.

Based on anthropological studies of recent and contemporary societies, Gillings and Pollard suggest that forests, clearings, and stones were important in Neolithic culture, not only as resources but as symbols; the site of Avebury occupied a convergence of these three elements. Neolithic activity at Avebury is evidenced by flint, animal bones, and pottery such as Peterborough ware dating from the early 4th and 3rd millennia BC. Five distinct areas of Neolithic activity have been identified within 500 m (1,600 ft) of Avebury; they include a scatter of flints along the line of the West Kennet Avenue – an avenue that connects Avebury with the Neolithic site of The Sanctuary. Pollard suggests that areas of activity in the Neolithic became important markers in the landscape.

Construction

The construction of large monuments such as those at Avebury indicates that a stable agrarian economy had developed in Britain by around 4,000–3,500 BC. The people who built them had to be secure enough to spend time on such non-essential activities. Avebury was one of a group of monumental sites that were established in this region during the Neolithic. Its monuments comprise the henge and associated long barrows, stone circles, avenues, and a causewayed enclosure. These monument types are not exclusive to the Avebury area. For example, Stonehenge features the same kinds of monuments, and in Dorset there is a henge on the edge of Dorchester and a causewayed enclosure at nearby Maiden Castle.[15] According to Caroline Malone, who worked for English Heritage as an inspector of monuments and was the curator of Avebury's Alexander Keiller Museum, it is possible that the monuments associated with Neolithic sites such as Avebury and Stonehenge constituted ritual or ceremonial centres.

Monument

Most of the surviving structure is composed of earthworks, known as the dykes, consisting of a massive ditch and external bank henge. Although the henge is not perfectly circular, it has a diameter of about 420 metres (460 yd). The only known comparable sites of similar date are only a quarter of the size of Avebury. The ditch alone was 21 metres (69 ft) wide and 11 metres (36 ft) deep, with a sample from its primary fill carbon dated to 3300 - 2630 BC (4300+/-90).[17] The excavation of the bank has demonstrated that it has been enlarged, presumably using material dug from the ditch, so it could be assumed that the construction of the ditch could have started at the earlier date, although speculation puts it nearer the later date.

Within the henge is a great outer circle. This is one of Europe's largest stone circles, with a diameter of 331.6 metres (1,088 ft), Britain's largest stone circle.[19] It was either contemporary with, or built around four or five centuries after the earthworks. There were originally 98 sarsen standing stones, some weighing in excess of 40 tons. The stones varied in height from 3.6 to 4.2 m, as exemplified at the north and south entrances. The fill from two of the stoneholes has been carbon dated to between 2900 and 2600 BC (3870+/-90, 4130+/-90)[20]

Nearer the middle of the monument are two additional, separate stone circles. The northern inner ring is 98 metres (322 ft) in diameter, but only two of its four standing stones remain upright. A cove of three stones stood in the middle, its entrance facing northeast.
 
The stone avenue

The southern inner ring was 108 metres (354 ft) in diameter before its destruction in the eighteenth century. The remaining sections of its arc now lie beneath the village buildings. A single large monolith, 5.5 metres (18 ft) high, stood in the centre along with an alignment of smaller stones.

The West Kennet Avenue, an avenue of paired stones, leads from the southeastern entrance of the henge; and traces of a second, the Beckhampton Avenue, lead out from the western entrance.

Archaeologist Aubrey Burl has conjectured a sequence of construction beginning with the erection of the North and South Circles around 2800 BC, followed by the Outer Circle and henge around two hundred years later, with the two avenues added around 2400 BC.

Findings of archaeological geophysics suggests that a timber circle of two concentric rings stood in the northeast sector of the outer circle. This has not yet been confirmed by excavation. A ploughed barrow is visible from the air in the northwestern quadrant.

The henge had four opposing entrances, two on a north by northwest and south by southeast line, and two on an east by northeast and west by southwest line.