Researchers are beginning to unravel the mystery of a series of puzzling circular geoglyphs that stretch from Syria to Saudi Arabia and draw comparison to Peru's 1,500-year-old Nazca Lines.

Discovered from the air in the 1920s, the Nazca Lines of Peru remain one of the most compelling ancient mysteries. Now, similar sets of lines in the Middle East are making headlines some 2,000 years after their construction.

Satellite and aerial photography revealed mysterious stone wheels that can be seen from the air but not from the ground. While they remain virtually unknown to the public, an aerial photography program in Jordan has used new satellite-mapping technologies to discover more about the mysterious shapes.

First discovered by a Royal Air Force pilot in 1927, the true extent of the structures was not revealed until recently.

Archaeologists say that the widely varied stone wheels may number in the thousands.

In Jordan alone we've got stone-built structures that are far more numerous than the Nazca Lines, far more extensive in the area that they cover, and far older, David Kennedy, a professor of classics and ancient history at the University of Western Australia, told Live Science.

The wheels are often found on lava fields and range between 82 and 230 feet in diameter.

People have probably walked over them, walked past them, for centuries, millennia, without having any clear idea what the shape was, Kennedy added.

The nomadic Bedouin people of the region call them the works of the old men.

Using old photos from pilots and satellite data from Google Earth, Kennedy and his team surveyed thousands of images. They found that the wheels form a variety of stone landscapes including kites (stone structures used to trap and kill animals), pendants (lines of stone cairns running from burials), and walls.

Adding to the mystery surrounding their purpose, none are presumed to be aligned with the stars and some of the wheels are found in isolation while others are clustered together.

While the designs are completely different than the Nazca Lines of South America, the function could be the same. Though the exact purpose of the structures remains unknown, the geoglyphs could have been places of worship or places for rituals connected to astronomical events or the seasons.

The full scope of the research will be revealed in an upcoming issue of the Journal of Archaeological Science.

Have a look at some of the photos below: