The Nasca Lines: "When I found out DFT was sending me to the Nasca lines of Peru, I was honestly VERY excited. The hummingbird, the spider, the monkey—these strange figures sprawling over the deserts have intrigued me for decades. (Note: Some people spell the word as Nazca, with a 'z.' This is also correct. However, UNESCO has opted to use an 's' and so do most of the people of Peru, so I'm going with an 's' here and in the show.)"

My first flight: "What you're seeing here is the real footage from my 'discovery' of a Nasca line, which I named 'The Flower.' At first, I thought Eduardo was pulling my leg—maybe to make the show a little more exciting—but he wasn't. This was the first time he had ever seen this geoglyph, and we took the GPS coordinates and photos to document it. In the coming days, I asked more and more people about the possibility of this being an actual discovery, and they confirmed that if Eduardo didn't know about it, it was a legitimate discovery. Huh, go figure! I think it's because we were the only plane in the sky that day (VERY rare) so Eduardo could fly in areas people don't usually travel. When I first pointed out 'the flower' his reaction was kind of like 'What are you talking about? There aren't any geoglyphs around here, man.' And just a few weeks ago, 50 more geoglyphs were discovered in another remote location, too. So the discovery isn't all that rare, but I'm still pretty proud of it."

The Astronomy Theory: "After a lifetime of studying the lines, Maria Reiche believed she had finally figured out their meaning.

Unfortunately, she apparently died before telling it to anyone. So while Ana Maria Cogorno represents much of Maria Reiche's work, I'm not sure that she has the secret to the lines. The truth is, if you took a bunch of sticks and threw them on the ground, 30 percent of them would point to SOME constellation on the horizon. The same 30 percent correlation exists between the lines and astronomical indicators, which means the Astronomy theory doesn't answer the 'what are they?' question."

Chauchilla and the Bones: "I've examined mummies, dived in flooded caves, and rappelled into tombs for this series, but nothing has been more strange and even spooky than the graveyard of Chauchilla. Seeing the human skulls and bones literally popping out of the desert sand left me (and Deborah) with a very somber feeling. It wasn't the bones as much as the quantity of bones—it was an overwhelming sensation of the dead being everywhere. I'm grateful I went, because it really did make me appreciate the culture of the Nasca as a people, but it was not the kind of place I'd race to go back to. Bad juju."

The Water Theory: "The Cantayoc aqueducts of Nasca are beautiful—the spirals, the stonework and the tunnels themselves are all a marvel of engineering, regardless of when they were built. A bit tight to crawl through, perhaps, but fun to explore nonetheless. The problem with the Water theory is that archeologists have only correlated 30 percent of the geoglyphs and lines with water sources. There is still active debate going on over this, as some argue the lines point to aquifers and fault lines which move water rather than the actual water sources, but the archeological community as a whole has not embraced the Water theory as the solution for the lines. So no luck here..."

The Blythe Intaglios: "What can I say... I live out West, I love archeology, and I'd never heard of the Blythe Intaglios. What makes these figures so special is that the Quetsan people and other local tribes and nations have a connection with the geoglyphs here which has not been broken. Their connection with rituals and ceremony suggest a use for the Nasca geoglyphs beyond the practical astronomy and water theories. Granted, it's not fair to extrapolate one culture's use in North America to a land thousands of miles away in South America, but as David says, 'it's a good place to start.'"

The Nasca Trophy Heads: "The bodiless heads and the thousands of skulls at the museum with Elsa were even spookier than the cemetary at Chauchilla. Holding the heads—feeling their fragility, their light sponginess—was something I'll not soon forget. Nor will walking through a room which I believe held over 10,000 skulls."

The Nasca Lines: "The ritual theory for the lines makes sense in light of the dances and vision quests I heard about at Blythe, Calif. and the ceremonial artifacts I saw in Lima, Peru. Of course, no one can say for sure what these lines represented. Personally, I think that each of the theories is partially correct. After all, the lines were built over many centuries and each artist/engineer could have been capturing or expressing a different aspect of his knowledge. So at one time, it may have been important to note a water source. Decades later, it could have been the stars. And after that, it may have been for dancing. Or maybe they were expressing all these things at the same time—there's no reason to think this isn't the case. In time, I'm hopeful we'll find out."