When McMahon arrived, she explained that the circle of rocks next to me was the remains of a house occupied in the Neolithic period (from 6000 to 4500 BCE), and that this area was once scattered with thriving settlements. Until recently, the prevailing wisdom was that this region had little human activity until the Bronze Age after 4000 BCE. But McMahon and her colleagues' work has unearthed a very different story: that Neolithic Saudi Arabia was a dynamic, intensely populated, complex landscape spread over a vast area.

Around me were more than 30 dwellings and tombs, and that was just a tiny fraction of the remains here. I tried to imagine the landscape as it may have been thousands of years ago: green, lush and teeming with people as they moved noisily round, herding goats and calling out to each other.

"The climate and inert landscape of Saudi Arabia means most of the archaeology is pretty well preserved on the surface from 5,000 to 8,000 years ago. So exactly as you see it is how it was all that time ago," McMahon said, explaining that understanding more about the lives of these early peoples could also shed light on how the large, dense settlements of Hegra and Dedan developed, and how cultural and technological changes in the region, such as irrigation farming, metalworking and written texts, came about over the following millennia.

"The cultural changes that took place following the Neolithic are huge, but we don't know a lot of how those changes happened," she said.

However, even in the hands of such experienced archaeologists, one AlUla discovery has continued to elude explanation. Spread over an area of a staggering 300,000 sq km and built to a fairly consistent type, are 1,600 monumental rectangular stone structures that also date to the Neolithic period. Initially named "gates" due to their appearance from the air, the structures were later renamed "mustatil", which translates to "rectangle" in Arabic.

uriginal https://www.bbc.com/travel/article/20220704-a-mysterious-cult-that-predates-stonehenge