Was it a temple for sun worship, a burial ground, an observatory, a healing centre or some kind of ancient calendar? The prehistoric monument known as Stonehenge is located in the English county of Wiltshire, about 8 miles (13 km) north of Salisbury. A circular arrangement of enormous standing stones set within earthworks, it continues to mystify the experts to this day.
Excavations have revealed that Stonehenge was built in four stages:
1. A series of ditches, postholes and pits, known as the Aubrey holes, dug around 3100 BC, presumably for ritual or religious ceremony.
2. More than 1000 years later, colossal bluestones formed into an incomplete double circle, perfectly aligned with the midsummer sunrise. The stones were either deposited close to the site by the Irish Sea Glacier or were transported by human endeavour from the Preseli Hills, 150 miles (240 km) away in modern-day Pembrokeshire in Wales.
3. In 2000 BC, the addition of 30 huge Oligocene-Miocene sarsen stones, transported by land from the Marlborough Downs some 25 miles away.
4. After a further 5 centuries, the arrangement of bluestones into the familiar horseshoe and circle visible today.
Architectural marvels like Stonehenge and the Egyptian pyramids have refused to divulge their secrets for thousands of years. Among the more outlandish theories is that they were constructed by extraterrestrials with superior engineering skills.
If Stonehenge was some kind of astronomical clock, imagine what a pain daylight saving adjustments must have been!