Machu Picchu is the ancient Inca citadel high in Peru's Andes, built in the 15th century.
The site stands about 2,430 metres above sea level on a mountain ridge above the Urubamba Valley. Archaeologists generally associate its construction with the reign of the Inca ruler Pachacuti, who expanded the empire during the fifteenth century. Its terraces, plazas, residences, and ritual structures were built from precisely fitted stone.
Machu Picchu was probably a royal estate or ceremonial and administrative center rather than the Inca capital. The site was not widely known internationally until the 1911 expedition led by Hiram Bingham, although local people were aware of it. It was never a completely “lost city” in the literal sense.
Cusco was the Inca imperial capital, while Chan Chan was the capital of the earlier Chimú civilization. Machu Picchu became a UNESCO World Heritage Site in 1983 and is one of Peru's best-known archaeological attractions.