Mideast riddle: Strange stone structures caught on camera

They stretch from Syria to Saudi Arabia, can be seen from the air but not the ground, and are virtually unknown to the public.

They are the Middle East's own version of the Nazca Lines -- ancient "geolyphs," or drawings, that span deserts in southern Peru -- and now, thanks to new satellite-mapping technologies, and an aerial photography program in Jordan, researchers are discovering more of them than ever before. They number well into the thousands.

Referred to by archaeologists as "wheels," these stone structures have a wide variety of designs, with a common one being a circle with spokes radiating inside. Researchers believe that they date back to antiquity, at least 2,000 years ago. They are often found on lava fields and range from 82 feet to 230 feet (25 meters to 70 meters) across.

Kennedy's new research, which will be published in a forthcoming issue of the Journal of Archaeological Science, reveals that these wheels form part of a variety of stone landscapes. These include kites (stone structures used for funnelling and killing animals); pendants (lines of stone cairns that run from burials); and walls, mysterious structures that meander across the landscape for up to several hundred feet and have no apparent practical use. 

His team's studies are part of a long-term aerial reconnaissance project that is looking at archaeological sites across Jordan. As of now, Kennedy and his colleagues are puzzled as to what the structures may have been used for or what meaning they held....