ement of upright bluestones. Current archaeological research shows that this site was constructed and modified on various phases, spanning several centuries:PERIOD I (c. 3100 - 2300 BCE) -- Neolithic Age The earliest portion of the complex, which dates to approximately 3100-2300 BCE., comprised a circular ditch of about 330 feet (100 meters) in diameter with an internal bank, and a north-eastern entrance Just inside the earth bank is a circle of 56 Aubrey holes (named Aubrey holes for their 17th-century discoverer, John Aubrey). Probably also dating to this time are the four Station Stones (only two of which survive) and, on the northeast side, an earthwork which runs from the break in the bank and ditch. The now fallen Slaughter Stone, located at the break in the bank and ditch, may date from the period, as well as the Heel Stone, located further out along the Avenue.PERIOD II (c. 2100 - 2000 BCE)People of the Beaker Culture built an earthwork approach road, now called the Avenue, to the entrance of the bank and ditch. The Beaker Culture found bluestone from the Preseli Mountains in southwestern Wales. With this, they set up the double concentric circle of Menhirs (large, rough-hewn standing stones) within the earlier ring. Both the Avenue and the double circle were orientated toward the summer solstice sunrise. The double circle was never completed and was dismantled during the following period. Ten upright stones arranged as five freestanding pairs with a single lintel (the so-called trulithons) were placed in the shape of a horseshoe. The trilithons were then enclosed within a circle of about 108 feet (33 meters) in diameter comprised originally of 30 neatly trimmed upright sandstone blocks (known today as sarsens). These stones, which stand on average 13 feet (4 metres) above the ground, are about 6.5 feet (2 metres) wide, and 3 feet (1 metre) thick, supported a continuous ring of sarsen lintels (held in place by tongue-and-groo...
