The story of Machu Picchu is quite a remarkable one and it is still unknown exactly what role the site played in Incan life. One thing that is clear is that it was a remarkably well hidden place, and well protected. Located far up in the mountains of Peru, visitors had to travel up long valleys littered with Incan check points and watch towers.
Remarkably, the Spanish conquistadors missed the site, and Bingham only discovered the site by chance. On a wet day in 1911, he travelled up the slopes with a few companions from his expedition. On meeting local peasants, they told him about ancient ruins that covered the area. To Bingham's amazement, he had found the lost Incan city of Machu Picchu.
In 1913, the site received a significant amount of publicity after the National Geographic Society devoted their entire April 1913 issue to Machu Picchu. Bingham made several more trips and conducted excavations on the site through 1915. He wrote a number of books and articles about Machu Picchu; his account, Lost City of the Incas, became a bestseller.