Newly discovered evidence of two large pits on the east and west sides of Stonehenge suggest that the area may have been recognized as a sacred site at a much earlier date than previously thought.
Archaeologists with the University of Birmingham believe the holes could have held stones, wooden posts or fires to mark the sunrise and sunset for a "processional route" used to celebrate the summer solstice before the well-known larger stones were erected.
The pits were found along the Cursus pathway, "two parallel linear ditches with banks either side closed off at the end," according to the BBC. Researchers also found a gap in the middle of the northern side of the Cursus, indicating a possible entry point for processions.
The Independent explains how researchers arrived at the new procession theory:
..The 'eureka moment' came when the computer calculations revealed that the midway point (the noon point) on the route aligned directly with the [center] of Stonehenge, which was precisely due south...
..The 'due south' noon alignment of the 'procession' route's mid-point could not occur if the Cursus itself had different dimensions, the design of that monument has to have been conceived specifically to attain that mid-point alignment with the [center] of Stonehenge.
The pits were discovered using non-invasive mapping techniques during a 2010 survey conducted by researchers from the University of Birmingham and the Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology in Vienna.
The survey, known as the Stonehenge Hidden Landscape Project, strives to "visually recreate the extraordinary prehistoric landscape surrounding Stonehenge," according to the news release.