This is the site of an archeological wonder, the Nazca lines.
I could go into a very detailed description, but you'd probably rather want to watch this vdieo:
The question still remains, why did these people put enormous amounts of work in something they were never fully able to see?
One explenaition is they were made to honor the gods, but maybe these gods were closer to these people then we think. For archeologists also found very strange skulls near the lines, and when i say strange, i mean really weird. Scientists have finally managed to do a reconstruction of how these people would have looked like, as is seen in this video:
But we do know the old american cultures are far more advanced and complex then you would think of societies that old. There are a lot of things we still don't understand, and maybe we will never understand it fully. But an interesting theory is that the mayans were visited by outsiders.
I am not saying the mayans were, or were not, visited by aliens, but this stuff is really interesting.