Machu Picchu, the 15th-century Inca citadel, is in Peru.
The site sits high in the Andes above the Urubamba Valley, at roughly 2,430 metres above sea level. Archaeologists generally associate its construction with the reign of the Inca ruler Pachacuti, who ruled during the 15th century. Its terraces, stone buildings, plazas, and sophisticated water channels were built from carefully fitted masonry.
Machu Picchu was probably abandoned in the 16th century during the Spanish conquest, although the Spanish did not record discovering it. American historian Hiram Bingham brought it to broad international attention in 1911, after local residents guided him to the ruins. The site is not the Inca capital—Cusco held that role—and it is frequently, but incorrectly, described as a “lost city.” UNESCO added Machu Picchu to its World Heritage List in 1983.