Which ancient civilisation built Machu Picchu?

The Inca built Machu Picchu in the fifteenth century, on a ridge high above the Urubamba river in what is now Peru. It appears to have been a royal estate rather than a city or a fortress, associated with the ruler Pachacuti, and it was abandoned around the time of the Spanish conquest without the Spanish ever finding it, which is why it survived so intact. The construction is the striking part. Inca masons cut stone blocks that fit together without mortar, so precisely that the joints resist a blade, and the walls slope slightly inward with trapezoidal doorways, a shape that helps them ride out the earthquakes common in the Andes. Terracing down the steep slopes provided farmland and, more importantly, drainage on ground that receives heavy rain. The Inca ran their vast empire without writing or the wheel, using knotted cords called quipu for records and a network of roads and runners.

The site was brought to international attention in 1911 by Hiram Bingham, though local people already knew of it.