The Construction

Constructed without the use of draft animals and shaped by stone tools, Stonehenge was erected many miles from the quarry from which the stones came. It is an amazing feat of engineering. Other then that, the two main materials of the Stonehenge, the bluestone and the sarsens, were difficult to obtain. The bluestone is a mixture of rocks found on the Preseli Mountains in SW Wales. The most widely accepted theory regards the arrival of the bluestones on Salisbury Plain as the result of human effort, with the route being partly overland and partly by water. Sarsen stones are hard-grained sandstone with with a silaceous cement. They were probably brought to the site from the Marlborough Downs, about 30 km to the north of Stonehenge.

Current archaeological research shows that this site was constructed and modified on various phases, spanning several centuries:

PRE-STONEHENGE (9th-8th millennium BC): at least 4 mesolithic pits which originally contained big pine posts, in a line about 200m from the present henge site.

Phase I

Stonehenge 1 (from 3100 BC): 

• consists of the circular bank and ditch, probably about 8 feet high and 300 feet in diameter.  
• Inside this circular ditch contains 56 Aubrey Holes which probably originally contained timber posts. Fred Hoyle has suggested that the 56 Aubrey holes are to predict eclipses.  
• In phase I, four marker stones were placed around the ring, two of these on mounds. These correspond to the Moon setting at its most Southerly point, Moon rising at its most Northerly point, the Sun rising at its most Northerly point and the Sun setting at its most Southerly point. These four alignments form an almost perfect rectangle. 

Phase II

• Pottery, animal bones, and cremated human remains placed in ditch. 
• Cremations are deposited in some of the partially filled Aubrey Holes. 
• complex of posts in interior and in entrance causeway are also constructed.

Phase III

1. Bluestones from Wales erected in q and r holes and then dismantled
2. Sarsen circle and trilithons erected, possibly also a bluestone setting which may have included trilithons, this latter then dismantled
3. Bluestone circle and oval setting
4. Arc of bluestones removed from oval to leave present horseshoe setting
5. Y and Z holes dug, probably for stones which were never erected; during this phase the avenue was also constructed.