They range from Syria to Saudi Arabia, is in the air, but not on the ground, and is almost unknown to the general public.
They own version of the Middle East Nazca lines - old "geolyphs", or drawings that cover the deserts of southern Peru - and now with the new satellite mapping technology, and a program of aerial photography Jordan researchers are discovering more of them than ever. Suman well into the thousands.
Designated by archaeologists as "wheels", these stone structures have a wide variety of models with a common is a circle with rays radiating from within. Scientists believe they date back to antiquity, at least 2,000 years ago. They are often found on the lava fields, ranging from 82 feet to 230 feet (25 meters to 70 meters) in diameter. [View Gallery structures wheel]
"Jordan alone there are a lot of stone structures such as the number of (), the Nazca Lines, a much wider region that they cover, and the very old," said David Kennedy, professor of classics and ancient history from University of Western Australia.
New research by Kennedy, to be published in an upcoming issue of the Journal of Archaeological Science, found that these wheels are part of a variety of scenarios rock. These include comets (stone structures used to channel and kill animals) Pendants (lines from the burial of Cairns), and the walls, mysterious structures that meander through the landscape of several hundred meters and have no obvious practical use.
Studies of his team are part of a long-term aerial survey that focuses on archaeological sites throughout Jordan. As of now, Kennedy and colleagues wonder why structures may have been used or what meaning they had. [Mysteries of the forgotten story]
Main area of expertise is in Roman archeology Kennedy, but he was fascinated by these structures when, as a student, read the stories of the pilots of the Royal Air Force flew in the 1920's on the road through Jordan by plane. "You can not help but be fascinated by these things," says Kennedy.
In fact, in 1927, RAF Flight Lieutenant Percy Maitland published a report on the ruins of the ancient journal. He reported the find in the "land of lava" and they said, with the other stone structures, known by the Bedouins as "works of the old men."
Kennedy and his team have studied the structures through aerial photos and Google Earth, the wheels are hard to glean from the land, says Kennedy.
"Sometimes when you're actually there on the site that you can make a kind of model, but not very easily," he said. "As if climbing a hundred feet or so, which to me makes perfect relief is the way."
The drawings must have been more clear when originally built. "People probably walk on them, went before them for centuries, millennia, without a clear idea of what was the shape."
(The team has created an image file of the wheels of several sites in the Middle East.)
What were they used?
To date, the wheel does not seem to have been excavated, making appointments, and to discover their goal more difficult. Study of the archaeologists in Google Earth before implies that one might be the remains of houses and cemeteries. Kennedy said that none of these explanations seems to work.
"There seems to be some vast cultural continuum in this region where people felt there was a need to build structures that were circular."
Some reels were found in isolation, while others are grouped. At one point, near Azraq Oasis, hundreds of them can coexist in a dozen groups. "Some of these collections around Azraq is truly remarkable," says Kennedy.
In Saudi Arabia, the Kennedy team are the wheel styles are very different: some are rectangular and not all the wheels, others are circular, but contain two rays that form a bar often aligned in the same direction as the sun rises and sets in the Middle East.
Those in Jordan and Syria, on the other hand, many rays does not appear to be in line with all astronomical phenomena. "Looking at many of them over the years, I was touched by any reasons in the way the shelves were built," says Kennedy.
Cairns was often associated with the wheels. Sometimes the wheel rim ring, sometimes between the spokes. Saudi Arabia seems to some to Cairns from the air, as they relate to the ancient tombs.
Meeting of the wheels is difficult because it seems prehistoric, but may date from as recently as 2000 years. The researchers noted that the wheels are often at the top of the kites, dating back 9000 years, but never the reverse. "This suggests that the wheels are the latest kites," says Kennedy.
Amelia Sparavigna, a physics professor at the Politecnico di Torino in Italy, told Science in a direct e-mail that it agrees with these structures can be described as geoglyphs, as the Nazca lines. "If we define a" geoglyph "as a billboard, because home artificial stone circles are geoglyphs" Sparavignawrote in his e-mail.
Wheels were also operating similar mysterious drawings in the Nazca desert. [Science as Art: Gallery]
"If we consider, more generally, the stone circles as places of ancestor worship, or places of rituals associated with astronomical events or with the seasons, they could have the same function  geoglyphs of South America Nazca lines, for example. The design is different, but function could be the same, "she wrote in her e-mail.
Kennedy said that for now the meaning of the wheel remains a mystery. "The question is: what