The most famous of all the ruins, seems to be suspended between two mountains and is often lost in the fog. It can be seen below the Urubamba Valley and is an enchanting place, especially since the Incas had not heard of the "wheel" when they built it. Machu Picchu was built in the mid-fifteenth century, but since its existence was not recorded by the Spanish conquerors, who occupied the place in 1530, nobody knows really what was the purpose of its construction. Many of the ruins i...