The earliest archaeological remains found in Britain are tools thought to have been made before 12000 BC, when Britain was still attached to the rest of Europe. No human bones from this period were found until 1912 when a skull that had characteristics of both humans and apes was found in a gravel pit in Sussex. The skull became known as Piltdown man . From geological evidence it was calculated that the skull belonged to somebody who lived more than two million years ago. Later scientific tests showed that it was not genuine and that the jaw of an ape had been attached with glue to a human skull and then treated to make it look very old. The earliest genuine human bones found in Britain are those of a woman from Swanscombe, Kent, who lived about 325 000 years ago.
Most Stone Age remains in Britain are much later and date from after 4000 BC, the Neolithic period. There is evidence of woodland being cleared for farming, and polished stone axes and fragments of pottery have been found. The remains of a Stone Age village built about 3100 BC can be seen at Skara Brae in the Orkneys. The houses were buried in sand after a storm in about 2000 BC and only found when another storm in 1850 blew the sand away.
Other Stone Age remains include long barrows , piles of earth up to 300 feet long, found mainly in England and Wales. They were used as burial mounds and sometimes have several rooms inside containing human and animal remains and pottery. Henges , circular areas surrounded by a ditch and a bank, may have been built as meeting places. One of the most impressive is at Avebury . It is large enough to contain the modern village of Avebury. A stone circle made of upright megaliths (= very large stones) up to 20 feet (6 metres) high was added inside the henge in about 2400 BC, at the end of the Stone Age. The henge at Britain’s best-known prehistoric monument , Stonehenge on Salisbury Plain , also dates from the Stone Age, though the circles of huge stones inside it date from about 2100 BC, the beginning of the Bronze Age .