Researchers say they have solved possibly one of the world's greatest mysteries - Stonehenge.
Located on Salisbury Plain in England, Stonehenge is a prehistoric monument claimed to have been constructed at around 2500 BC. The ancient wonder has baffled people around the world for centuries, but maybe now some of the theories of its origin can be put to rest.
Researchers claim the site is a giant solar system to help people keep track of the days, weeks and months.
One of the researchers, Professor Timothy Darvill from Bournemouth University, said the site was based on a solar year of 365.25 days, where weeks were 10 days long and there were more months than there are today.
"Such a solar calendar was developed in the eastern Mediterranean in the centuries after 3000 BC, was adopted in Egypt as the Civil Calendar around 2700 BC, and was widely used at the start of the Old Kingdom about 2600 BC," Prof Darvill said in a media release.
The 'giant solar system' may then link the United Kingdom to ancient Egypt, as it could have stemmed from the influence of one of these cultures.
But how does it work?
"The proposed calendar works in a very straightforward way," Prof Darvill said.
"Each of the 30 stones in the sarsen circle represents a day within a month, itself divided into three weeks each of 10 days."
The stones in the circle mark the start of each week and a leap day every four years have been accounted for by four stones outside the sarsen circle, only two of which currently remain intact.
"The intercalary month, probably dedicated to the deities of the site, is represented by the five Trilithons in the centre of the site," said Prof Darvill. "The four Station Stones outside the Sarsen Circle provide markers to notch-up until a leap day."
He says the Winter and Summer solstices would be framed by the same pairs of stones every year and any errors in counting the days would be easily detectable as the sun would be in the wrong place on the solstices.
Prof Darvill hopes the identification of a solar calender at Stonehenge could transform how we see it and help with further research.
"Finding a solar calendar represented in the architecture of Stonehenge opens up a whole new way of seeing the monument as a place for the living," he said, "a place where the timing of ceremonies and festivals was connected to the very fabric of the universe and celestial movements in the heavens."
