Mysterious stone structures discovered three years ago in Saudi Arabia are now believed by archaeologists to be among the oldest in the world, dating back some 7,000 years, making them older than Egypt's famed Giza Pyramids and England's Stonehenge which are an estimated 4,500 and 5,000 years old respectively.
Once called "gates", hundreds of the rectangular-shaped stones, now referred to as "mustatils" – after the Arabic word for rectangle – were possibly used for rituals according to a recently published report by a team of researchers in the journal the Holocene.
"The mustatil phenomenon represents a remarkable development of monumental architecture, as hundreds of these structures were built in northwest Arabia," says the paper.
"This 'monumental landscape' represents one of the earliest large-scale forms of monumental stone structure construction anywhere in the world."
— عادل | Adel (@ET_adelalshehri) August 25, 2020
Researchers used radiocarbon dating of charcoal found inside one of the structures to date them back to 5000 BC. The structures range from 15 metres to over 600 metres long. Further analysis of the monuments found they once had a platform built at either end of the rectangle, with some displaying geometric designs "unlike any seen from other rock art contexts" in the region, the article said.
The first discovered mustatils were made in the desert lava field of Harrat Khaybar, however a team of archaeologists are carrying out similar investigations having identified mustatils in the Nefud Desert in the north of the country using high-resolution satellite images and data from Google Earth.
It "is quite possible that these structures would have been visually spectacular, and perhaps quite extensively painted," head of the mission, Huw Groucutt, told the website Live Science. Groucutt is also quoted by the Max Planck Institute as saying that "Perhaps they were sites of animal sacrifices or feasts."
The researchers wrote in the Holocene that "Between 10 and six thousand years ago the Arabian Peninsula saw the most recent of the 'Green Arabia' periods when increased rainfall transformed this generally arid region." However, this period didn't last long as once the region dried up, the rectangular stone structures stopped appearing in the archaeological record. These changes in the local environment likely led to the emergence of the Neolithic period in Arabia when local cultures were radically transformed, suggests an article on Ancient Origins.