Stonehenge may have been built to symbolize the unity of Stone Age Britain. This idea may explain why so many of the stones that make up the monument were transported from long distances.
Located on Salisbury Plain in southern England, Stonehenge appears to have been built in stages between 3100 and 1600 BC. It has a vertical sarsen stone outer ring, above which is a horizontal lintel. Inside it is a small ring of vertical bluestones and many other stones, including horizontal stones.
Source: www.newscientist.com