DRUIDS, mystics, UFO enthusiasts and even the occasional rock star have converged in awe beneath its arcane structure.
Now, after its eternal mysteries have driven generations of archaeologists round in circles, a lucid new theory has suggested Stonehenge was conceived for a more prosaic purpose - as a Neolithic health centre.

The latest hypothesis surrounding one of the world's best known but least understood landmarks suggests the world heritage site was a precursor to Lourdes.

The claim follows the first dig inside Stonehenge's concentric circles for nearly half a century. The excavation this spring unearthed many fragments of bluestone, accorded healing powers in medieval folklore and literature, and seemingly taken as lucky charms by visitors to Salisbury Plain.

The disclosure justifies the extraordinary feat of Stonehenge's construction, in which bluestone rocks were transported over land and sea from a quarry known as Carn Menyn in Pembrokeshire's Preseli Hills, 150 miles away.

Professor Tim Darvill of Bournemouth University revealed radiocarbon dating suggested the monument was three centuries younger than previous theories suggested, raised in 2300BC.

The date correlates with the grave of the so-called Amesbury Archer, an adult male with a healed head wound and an injured left leg excavated in 2002. With the discovery of an "abnormal number" of other non- native bodies showing signs of serious disease, researchers believe Europe's ill may have came to Stonehenge in search of good health.

"(The stones'] meaning and importance to prehistoric people were sufficiently powerful to warrant the investment of time, effort and resources to move them from the Preseli Hills to the Wessex Downs," Prof Darvill said.

Professor Geoffrey Wainwright, president of the Society of Antiquaries and fellow project leader of the dig alongside Prof Darvill, said a river running through the Preseli Hills had been dammed to create pools for the sick to bathe in. Nearby prehistoric art and burial cairns strengthened the connection between Stonehenge and healing properties.

"The wells of the Preseli Hills were considered to have wonderful healing powers, and that is a good reason why the bluestones were transported," he reasoned.

Few would be so bold as to suggest the latest theory offers a definitive answer to Stonehenge's myriad secrets. Explanations proliferate, not all of them upstanding examples of antiquarian study. They include the creation of the megaliths by giants, and mention of alien spaceship landing pads.

Sagely, Prof Darvill and Prof Wainwright believe the conjecture - the more sensible among it, anyway - can happily co-exist with their own theories.

"Stonehenge probably had more than one purpose, so I have no problem with other people's interpretations," said Prof Wainwright.

English Heritage, the guardian of Stonehenge, agreed to the dig following consent by the Secretary of State for Culture, Media and Sport. Druids also gave their blessings.

A Timewatch documentary on the dig will be screened on BBC2 at 8pm this Saturday.

TIMELINE

3000BC: A large earthwork, or henge, is built

2900BC: Wooden posts erected and later dismantled. Cremation burials placed throughout site

2300BC: Bluestones taken to Stonehenge, followed by Sarsen stones

1901: Landowner Sir Edmond Antrobus fences off the site, charging one shilling admission. Uproar follows

1915: Stonehenge bought by Cecil Chubb at auction for £6,600. He later gives it to the nation

1923: DH Thomas of the Geological Survey discovers the bluestones came from Wales

1978: Skeleton of young male found, with flint arrows wedged in his ribs

1986: Monument becomes World Heritage Site

2002: Discovery of the Amesbury Archer