Which ancient Inca citadel stands high in Peru’s Andes Mountains?

Machu Picchu is the ancient Inca citadel high in Peru’s Andes Mountains.

The site lies about 2,430 metres above sea level on a mountain ridge above the Urubamba Valley. Inca rulers probably built it in the 15th century, during the reign of Pachacuti, although its exact purpose remains debated.

Machu Picchu includes terraces, plazas, temples, residences, and carefully fitted stonework. Its agricultural terraces helped manage steep slopes and water, while sophisticated drainage reduced the risk of erosion in a wet mountain environment.

The site was not known to the outside world in the same way as major colonial cities, and it was not destroyed by the Spanish conquest. Hiram Bingham publicized it internationally after visiting in 1911, though local people already knew the ruins. UNESCO listed Machu Picchu as a World Heritage Site in 1983.