Nazca lines found in the Middle East.

[Swampy]

The ancient South Americans created large pictograms of shapes that can only be seen from the air, and similar lines have been found in the Middle East.

I have always wondered why ancients would create such structures, and I can only go with the so-called fringe explanation that they had some sort of flight capability, whether it was from ancient aliens or from hot air balloons.

[John H. Sime]

These structures remind me more of the North American Indian practice of building "medicine wheels", also sometimes done on extremely remote places such as mountain tops. Then of course there are the various circular structures in Europe such as Stonehenge. The obvious symbolic and mythic value of a circle as relating to the pattern of the year comes to mind, as does the potential of using such a structure to track astral events. Of course, worldwide, primitive as well as modern cultures use the circle as a form of gathering of crowds for rituals. All of this goes without turning to the ET explanation, which should not be ignored.