The nearly 400 stone structures, nicknamed “gates” because they resembled field gates from satellite images, were clustered around the volcanic region of Harrat Khaybar in Saudi Arabia.
And researchers were perplexed as to what these structures were used for and who built them, or if they were the earliest “Works of the Old Men,” pertaining to ancient geoglyphs that stretch from Syria to Saudi Arabia.
“We tend to think of Saudi Arabia as desert, but in practice there’s a huge archaeological treasure trove out there and it needs to be identified and mapped,” said Dr. David Kennedy, an archaeology professor at the University of Western Australia, in an article from The New York Times.
“You can’t see them very well from the ground level, but once you get up a few hundred feet, or with a satellite even higher, they stand out beautifully.”
A paper authored Dr. Kennedy is set to appear in the November issue of the journal Arabian Archaeology and Epigraphy.
Dr. Kennedy has been studying the angular and wheel-like structures scattered over Jordan’s lava field, or harrat, since 1997 but did not have the opportunity to look more closely at the ancient structures in neighboring Saudi Arabia because of access restrictions.
“We would have loved to fly across into Saudi Arabia to take images. But you never get the permission,” Dr. Kennedy said. “And then along comes Google Earth.”
The mystery of the stone structures started in 2004 when Dr. Abdullah Al-Saeed, a neurologist and founder of the Desert Team, a group of amateur archaeologists in Saudi Arabia, explored the lava fields of Harrat Khaybar. He saw walls of stones stacked about three feet high, but said that he did not appreciate their unique design at that time.
Then the break came in 2008 when Dr. Al-Saaed went back to the same spot using Google Earth.
“When I saw the updated images of Harrat Khaybar from Google Earth, I was literally stunned and could not sleep that night,” Dr. Al-Saeed said. “Flying like a bird all over the Harrat from one enigmatic structure to another! How come we passed by these structures without appreciating their design?”
Further investigation and some Google images sent to archaeologists such Dr. Kennedy received bewildering feedbacks.
That’s what Dr. Kennedy said he felt when he first saw the satellite images, as was confronted with structures quite different from anything he had ever seen before.
Varying in size, the longest gate measures more than half a kilometer, while the shortest is just 13 meters and the spaces between them differing from miles apart to “almost touching.”
Dr. Kennedy has spent almost a decade cataloging nearly 400 gates and hoped his next step would be to lead a research team that would collect samples to carbon age the lava fields, and even the stone walls to determine the timing of their construction.
“More will be found as more people get involved in scouring the landscape from satellite imagery,” he said.