Machu Picchu is the most important archaeological as well as tourist site in Peru. It’s located 80km from Cuzco at 7,875 ft above sea level, seemingly precariously built on a steep mountain ridge over the raging Urubamba river. The city was “discovered” by Yale Professor Hiram Bingham in 1911 hidden in dense jungle, nearly 400 years after the Spanish defeated the Incas who built the city. Although the Spanish razed the Inca world they conquered, they never found Machu-Picchu.

The city is now presumed to have been built around 1460 and remains more or less in tact from that time. There are various theories as to its purpose -- an imperial retreat, commercial way-station or border fortress -- and the interior of the city is composed of structures supporting all these possibilities. There are individual domiciles of various sizes, meeting areas, parks, aqueducts, agricultural terraces and even astronomical stations, in addition to the Inca’s important religious buildings and monuments.

Machu Picchu was built in the classical Inca style, with polished dry-stone walls. No mortar was used in the mostly airtight sealing of the granite boulders used for construction. It remains a mystery how these heavy stones were brought up the steep precipice.

Nearly a half million tourists visit Machu Picchu every year. It is the single-most visited tourist site in South America.