Researchers have recently analyzed the ages of mysterious stone formations that are found across the Middle East, with two of these wheel-shaped structures being approximately 8,500 years old. However, estimates of the age of another, near-identical complex a continent away, might hint at a much earlier origin.

Thousands of these structures are found across the Arab region, forming various shapes, including wheels, lines, and meandering walls. Traditionally referred to by the Bedouin as "works of the old men," these structures "demonstrate specific geometric patterns and extend from a few tens of meters up to several kilometers, evoking parallels to the well-known system of geometric lines of Nazca, Peru," according to one paper published in the Journal of Archaeological Science. As with the Nazca lines, these formations are difficult to see from the ground, but are readily visible from the air.

Using a dating technique called optically stimulated luminescence (OSL) on two of the circular formations found in Wadi Wisad, in Jordan’s Black Desert, researchers found that one of the circles was dated to about 8,500 BP, and the other appeared to have been repaired or remodeled around 5,500 years ago. In 6,500 BCE, the area was inhabited, with a more favorable climate than what is found today. No-one has been able to divine the true purpose of the majority of the formations, although one circle in the Azraq Oasis appears to be an astronomical observatory, as it lines up with the rising sun on the winter solstice.

However, despite how widespread they are across the Middle-East, these formations are not alone in the world, as thousands of near-identical structures have been found, spread in a network across South Africa over an area twice the size of Texas. While no formal academic studies appear to have been conducted on the South African formations, investigations into the stone network by Michael Tellinger and Johan Heine, amongst others, have yielded similar results to the Arabian findings, except for one fascinating discovery.

Connected to the African network is a site called "Adam’s Calendar", a series of standing stones, set up in a similar fashion to Stonehenge, and presumed to be at least as old as the stone circles it accompanies. Early archaeoastronomy estimates placed it’s alignment with the stars in Orion’s Belt at about 75,000 years ago. However, after missing portions of the site’s stones were reconstructed, the date of alignment had to be pushed back to between 160,000 and 200,000 years ago — extremely far into humankind’s prehistory.