of logs which the large stones were rolled along. Another megalith transport theory involves the use of a type of sleigh running on a track greased with animal fat. Such an experiment with a sleigh carrying a 40-ton slab of stone was successfully conducted near Stonehenge in 1995. A team of more than 100 workers managed to push and pull the slab along the journey from the Marlborough Downs. Proposed functions for the site include usage as an astronomical observatory or as a religious site. In the 1960s Gerald Hawkins described in detail how the site was apparently set out to observe the sun and moon over a recurring 56-year cycle. More recently two major new theories have been proposed. Geoffrey Wainwright, president of the Society of Antiquaries of London, and Timothy Darvill, of Bournemouth University, have suggested that Stonehenge was a place of healing—the primeval equivalent of Lourdes. They argue that this accounts for the high number of burials in the area and for the evidence of trauma deformity in some of the graves. However, they do concede that the site was probably multifunctional and used for ancestor worship as well. Isotope analysis indicates that some of the buried individuals were from other regions. A teenage boy buried approximately 1550 BC was raised near the Mediterranean Sea; a metal worker from 2300 BC dubbed the "Amesbury Archer" grew up near the Alpine foothills of Germany; and the "Boscombe Bowmen" probably arrived from Wales or Brittany, France. On the other hand, Mike Parker Pearson of Sheffield University has suggested that Stonehenge was part of a ritual landscape and was joined to Durrington Walls by their corresponding avenues and the River Avon. He suggests that the area around Durrington Walls Henge was a place of the living, whilst Stonehenge was a domain of the dead. A journey along the Avon to reach Stonehenge was part of a ritual passage from life to death, to celebrate past ancestors and the recently deceased. Both explanations were first mooted in the twelfth century by Geoffrey of Monmouth, who extolled the curative properties of the stones and was also the first to advance the idea that Stonehenge was constructed as a funerary monument. Whatever religious, mystical or spiritual elements were central to Stonehenge, its design includes a celestial observatory function, which might have allowed prediction of eclipse, solstice, equinox and other celestial events important to