Lost city Inca site situated on a mountain ridge above the Urubamba Valley in Peru. Often referred to as the "Lost City of the Incas", it is perhaps the most familiar icon of the Inca World. Machu Picchu was built around 1450, at the height of the Inca Empire. It was abandoned just over 100 years later, in 1572, as a belated result of the Spanish Conquest. It is possible that most of its inhabitants died from smallpox introduced by travelers before the Spanish conquistadors arrived in the area. In 1911, Melchor Arteaga led the explorer Hiram Bingham to Machu Picchu, which
Machu Picchu northwest edge of the rock platform points out the Solstice Window to within 2’ of the 15th century June solstice rising Sun. For comparison, the angular diameter of the Sun is 6'. The Inca constellation Qullca, storehouse, can be viewed out the Qullqa Window at sunset during the 15th century June Solstice, hence the window's name. At the same time, the Pleaides are in the opposite end of the sky. Also seen through this window on this night are the constellations Llamacnawin, Llama, Unallamacha, Machacuay, and the star Pachapacariq Chaska (Canopus). The "Intihuatana" stone is one of many ritual stones