Which civilization built Machu Picchu high in Peru's Andes during the 15th century?

The Inca civilization built Machu Picchu high in Peru's Andes during the 15th century.

Machu Picchu is a stone settlement situated about 2,430 metres above sea level near Cusco. Archaeologists generally associate its construction with the reign of Pachacuti, the Inca ruler who expanded the empire during the 1400s. The site includes terraces, plazas, temples and carefully fitted masonry.

Its exact purpose is not known with certainty. Many researchers interpret it as a royal estate or seasonal retreat, while its religious buildings and astronomical alignments show that ceremonial activity was also important. The location may have combined political, agricultural and spiritual functions.

Spanish chroniclers did not record the site clearly, and it was largely unknown internationally until Hiram Bingham publicized it in 1911. Machu Picchu was not the Inca capital; that was Cusco. The Inca Empire fell to Spanish forces in the 16th century.