Stonehenge

Stonehenge stands on Salisbury Plain in Wiltshire. The sarsen trilithons weigh up to 25 tonnes each. The smaller bluestones, arranged in an inner ring and horseshoe, weigh up to four tonnes and were transported roughly 150 miles from the Preseli Hills in southwest Wales. No one has settled the question of how or why.

The Ringing Stones

The bluestones are spotted dolerite, an ignite rock that produces a clear, bell-like tone when struck. Researchers from the Royal College of Art tested stones in the Preseli Hills and found that a significant proportion are “ringing rocks,” producing metallic sounds when hit with a hammerstone. Several of the Preseli source stones show impact marks consistent with centuries of deliberate striking.

The question is whether Neolithic people selected and transported these specific stones because of their acoustic properties. The hypothesis, proposed by researchers at Bournemouth University and the University of Bristol, suggests that Stonehenge may have been as much an instrument as a monument. The acoustic environment inside the stone circle, when complete, would have produced unusual reverberations and standing waves.

The Alignments

The axis of Stonehenge aligns with the midsummer sunrise and midwinter sunset. The Avenue, a processional path, runs from the monument to the River Avon. The solstice alignment is precise enough that it cannot be accidental but crude enough that it was likely achieved through observation rather than mathematics.

Visiting

Stonehenge is managed by English Heritage. A visitor centre with exhibition space stands about two kilometres from the stones. Access to the stone circle itself is by timed ticket. Special access visits that allow entry inside the circle can be booked in advance for early morning or late evening. The site is about 90 minutes from London by car.