13.5078°S, 71.9822°W.
Sacsayhuaman is the monumental walled complex on the hill above Cusco, Peru, built during the reigns of Pachacuti and his successors in the second half of the 15th century. The site is dominated by three tiers of zig-zag cyclopean walls running for 360 metres, built of limestone and andesite blocks, the largest weighing an estimated 120 to 200 tonnes — placed without mortar in tight polygonal joints that still admit no blade. Pedro Sancho, secretary to Francisco Pizarro, recorded the construction and dimensions in 1534 shortly after the conquest. A major battle of the 1536 Manco Inca uprising was fought here, after which the upper towers were dismantled by the Spanish for building stone reused in colonial Cusco. Three principal towers — Muyuq Marka, Salla Marka, and Pawqa Marka — once stood on the upper terrace; only the foundations remain.
The largest stones at the entrance to the lowest terrace still stand exactly as the Inca masons set them.