In this part of Wales, the healing power of the bluestones is the stuff of myth and legend.

BBC: Unlocking Stonehenge's secrets

It's from here that the bluestones began their 200-mile journey, 4, 500 years ago.

BBC: Unlocking Stonehenge's secrets

Professors Darvill and Wainwright say that finding out more about the history of the bluestones could be key to solving the mystery of why the 4, 500-year-old landmark was erected.

BBC: 'Breakthrough' at Stonehenge dig

They believe that it wasn't just chance that brought the bluestones to Stonehenge first, but power - to them it's the bluestones that made Stonehenge the greatest henge of them all.

BBC: Unlocking Stonehenge's secrets

They believe that the bluestones, which were transported 250km (150 miles) from the Preseli Hills in Wales to the Salisbury Plain in Wiltshire, were brought to the site because the ancient people believed they had healing properties.

BBC: 'Breakthrough' at Stonehenge dig