The prehistoric megalithic monument consists of a henge, 56 pits known as Aubrey Holes positioned in such a way as to have possible use as an astronomical calendar, and a number of presumably fallen stones, standing stones and stone structures.
Stonehenge is surrounded by more than 400 burial mounds.
Stonehenge is believed to have been constructed over a period of 3,000 years beginning over 50 centuries ago around 3,100 BC. (Johnson, 2008, pp 110)
While no one knows for certain who built Stonehenge, why they built it ...