Spider
When Suzanne and I decided where to spend our limited time in Peru, we agreed that the Nasca lines are a unique sight in the world, and opted to put Lake Titicaca on the visit-next-time list.
The astronaut
I remember first seeing the Nasca lines on TV when I was a kid. The narrator spoke about how these amazing lines, that only make sense when viewed from a plane, were carved on the desert surface a thousand years before airplanes were invented.
Humming bird
How could the stone-age natives of this harsh and arid land know how to do this? And why would they take valuable time and energy to do it? The TV documentary suggested aliens from outer-space as the most logical explanation, which seemed to make sense to my 13-year-old mind. And when some of the images drawn on the desert appeared to be an astronaut and landing strips – well that sort of proved it – it must be aliens!
flying the Nasca Lines
So, I was excited to finally get out there and see the tangible evidence of extraterrestrial intervention. Patrick was quickly convinced that it is the work of aliens, Alex wasn’t so sure. While we waited for our flight in the little airport set up in the desert just for the purpose of flying tourists over the lines a more modern documentary played on the TV above our seats.
Nasca mummy
Apparently the current thinking is that the Nasca people who lived in this area long ago may not have required alien intervention to create the lines. A more likely hypothesis is that they used basic surveying techniques to scale up smaller drawings to a size that can be seen from the heavens. 
And since they lived in a very harsh part of the world that is prone to drought, they probably had good reasons to attempt communications with their gods to ask for rain.
The trenches in the desert that make the lines are only a few centimeters deep, but the unique geology and weather of the area allow the lines to stay in place for centuries. After our tour both Patrick is convinced the entire thing was created by aliens. Alex think aliens were involved somehow with the Nasca people. Suzanne was glad she took Dramamine before the flight. 
As for me, I think it is impressive that these hardy folks, with only stone-age technology available to them, developed methods to survey the desert floor and draw diagrams for their gods. It is fun to think that aliens might have a hand in human affairs – but I think it is much more impressive what humans have accomplished over the years with a little imagination, motivation, and basic geometry.
Sherrys Abroad 