Machu Picchu: The Lost City of the Inca
Machu Picchu — built at approximately 2,430 meters above sea level on a narrow mountain ridge above the Sacred Valley of the Incas, constructed around 1450 CE under the Sapa Inca Pachacuti, abandoned approximately a century later as the Spanish conquest destroyed the civilization that built it — was unknown to the outside world until the American explorer Hiram Bingham was led to it by a local farmer in July 1911. What Bingham found was a city that appeared never to have been looted: 172 structures arranged in distinct sacred, agricultural, and residential zones, their dry-stone construction of such precision that the joints between irregularly shaped granite blocks cannot accept a sheet of paper. The Inca built without mortar and without metal tools. They built in an active seismic zone, and their architecture has survived major earthquakes that would destroy modern constructions — because the buildings sway rather than crack, their irregular stones locking more securely under stress....