ancient

National Geographic explores the building techniques at Machu Picchu. Temples, altars and residences of this steep mountain city have resisted torrential rains, landslides and earth tremors since being abandoned by the Incas. (46 min)

What if life on Earth began in outer space? This updated History Channel documentary explores evidence of super-human influences on ancient man and embarks on an around-the-world search for answers. (90 min, 9 segments)

Episode 2 of the BBC documentary series The Story of Math gives due credit to the East - China, India and Arabia in the history of mathematics. (58 min, 6 segments)

In the first episode, The Story of Maths is the story of civilization, of human history starting with the need to quantify. (58 min)