Desc: Nasca Lines: The Buried Secrets: Directed by Philip Day. In southern Peru lies one of mankind's greatest mysteries - 1000's of giant shapes etched into the desert sands. We reveal who made them and why. Etched, as if by giants, onto the arid moonscape of Peru's southern desert lies one of man's greatest mysteries; the Nasca Lines. More than 15,000 geometric and animal-like patterns have been discovered criss-crossing the pampas like a vast puzzle. Who built them and what was their purpose? Ancient racetracks, landing strips for aliens, or perhaps a giant astronomical calendar? And are the Lines connected to the gruesome discovery of large cache's of severed human heads. Now, after decades of misunderstanding, modern archaeology may finally have the answer. Excavations in the surrounding mountains are uncovering extraordinary clues about the people who made them and why. A long since vanished people, called the Nasca, flourished here between 200BC and 700AD. But the harsh environment led them to extreme measures in order to survive. Archaeologist Christina Conlee recently made an extraordinary find: the skeleton of a young male, ceremonially buried but showing gruesome evidence of decapitation. In place of the missing human head, a ceramic "head jar" decorated with a striking image of a decapitated head with a tree sprouting from its skull. Conlee wonders who this person was? Why was he beheaded and yet buried with honor. Was he a captive taken in battle, or could he have been a willing sacrifice? And did his decapitation have anything to do with the lines? The discovery of large caches of human heads adds grisly weight to Conlee's theories and helps unravel on of man's great mysteries.