New dates for two massive circular wooden enclosures built at West Kennet, close to Avebury (Wiltshire, England), show they predate the first stones erected at nearby Stonehenge by about 800 years. Archaeologists think they were used for only a short time about 5,300 years ago, then purposely burned.
     Study co-author Alex Bayliss, a statistical archaeologist with Historic England, says: "It's completely unlike anything we've ever found in the British prehistory."
     The area around Stonehenge is saturated with ancient sites. Bones found near Stonehenge suggest that the area was a wild-auroch hunting ground long before the monument was built. Avebury has its own henge monument. Silbury Hill, the largest prehistoric artificial chalk mound, stands nearby. The remains of a Neolithic settlement called Durrington Walls shows signs of ancient feasting, and may have been where the builders of Stonehenge lived while working there.
     The wooden circles at West Kennet were discovered when a pipeline was being laid in the 1960s and 70s. In the late 80s and early 90s, Cardiff University archaeologist Alasdair Whittle led a small excavation which found charred remains, and deduced that two immense circles had been built side-by-side with only a small gap between them. One was a single ring about 250 metres in diameter, the other a concentric double ring about 200 metres in diameter.
     The enclosures were probably built by digging ditches and placing oak posts into sockets in the ground creating a huge palisade. The posts were very closely set; around 4,000 trees would have been needed.
     Whittle's team originally carbon-dated a shard of pottery found in one of the post holes to around 2500 BCE. Improved techniques available to Bayliss' team push the dates for charred remains from post holes, animal bones, and fragments of pottery back a further 800 years to 3,300 BCE - a period for which relatively little archaeological evidence exists.
     Her team suspects the two enclosures were used as a gathering place, but not for long; few other remains of human occupation dating to the period were found.

Edited from BBC News, LiveScience (8 June 2017)