Machu Picchu

Surrounded by four holy mountains and hidden at an elevation of 7,710 feet (2,350 meters) in the Peruvian Andes, the enigmatic city of Machu Picchu was never found and sacked by the Spanish; it was simply mysteriously abandoned by the Incas and recovered by nature. Since its dramatic rediscovery in 1911 by explorer and archaeologist Hiram Bingham III (1875-1956), speculation has surrounded this breathtaking "Lost City of the Incas." Today there is consensus for the theory that it was a royal estate built for Pachacuti, a legendary Inca warrior emperor of the 15th century who was responsible for completing several massive stone construction projects during his lifetime.
The site was extraordinarily well-engineered even by today's standards, and the skill with which it was constructed is even more amazing when we consider that the builders had neither iron tools nor use of the wheel. The majority of the 90-year construction process was spent in planning, soil stabilization, drainage, foundations, habitat and the development of an elaborate gravity-fed spring water system with a stairway of 16 fountains. The precipitous slopes were stabilized with over 700 highly permeable terraces to handle the superabundant average rainfall of 72 inches a year, most of which falls during the seven-month rainy season. The terraces not only supported over 200 stone buildings and numerous trails but also provided space for agricultural activity. The many faceted stone masonry of the structures evidences phenomenal craftsmanship, with individual stones precisely fitting together like an intricate puzzle without the use of mortar. The fine Inca stonework at Machu Picchu has withstood the deprecation of time, surviving as yet for over 500 years.