In this Monday March 31, 2008 file photo, archaeology students Steve Bush, right, and Sam Ferguson, left, sieve through earth amongst the stones at Stonehenge, England.
Archaeologists probing the secrets of Stonehenge, Britain's most famous prehistoric monument, said on Monday it may have been an ancient pilgrimage site for the sick who believed its stones had healing qualities.
It has always been a mystery why bluestones, the smaller stones that form part of the circle, were transported around 155 miles from Preseli Hills in Wales to Wiltshire in southern England.
Archaeologists from Bournemouth University, who carried out the dig in April -- the first at Stonehenge since 1964 -- believe the bluestones were revered as healing stones.
"It was the magical qualities of these stones which ... transformed the monument and made it a place of pilgrimage for the sick and injured of the Neolithic world," a statement from the archaeologist team said.
Geoffrey Wainwright, president of the Society of Antiquaries of London and one of the experts leading the work, told BBC radio that one reason which lead to the conclusion was because a number of the burials around Stonehenge showed signs of trauma and deformity.
The archaeologists said in the statement that radio-carbon dating put the construction of the circle of bluestones at between 2,400 B.C. and 2,200 B.C., a few centuries later than originally thought.
But they found fragments of charcoal dating from before 7,000 B.C., showing humans were active in the area much earlier than previously thought.
During the excavation at the World Heritage Site on Salisbury Plain, the researchers also found a beaker pottery fragment, Roman ceramics and ancient stone hammers.
"We now know, much to our surprise and delight, that Stonehenge was not just a prehistoric monument, it was a Roman and mediaeval monument," said Wainwright.
Another of the team leaders, Tim Darvill of Bournemouth University, said the bluestones appeared central to the purpose of Stonehenge although it may have had more than one function.
Other theories about Stonehenge are that it was a religious site or that it acted as a calendar.