Nazca Lines

The small desert town of Nazca hosts the worlds largest sand dune and a series of markings in the desert that have baffled scientists since 1941. Now a UNESCO World Heritage Site and covering a huge area, the Nazca Lines are a mysterious  collection of geometrical lines and shapes resembling, among others, a killer whale, hummingbird and monkey, and so large that they can only be appreciated from the air. The function of the ancient artworks, which predate the Incas by thousands of years, is still a mystery: some theorists talk of ancient running tracks or even landing strips for extraterrestrials.