View of Saksaywaman, a fortress in the foothills north of Cusco, historic capital of the Inca Empire, in today's Peru. The Killke culture started the fortress in the early twelfth century and the Incas expanded it starting in the thirteenth century. The dry stone walls are made of huge stones that are cut so precisely that they fit together without mortar.

View of Saksaywaman, a fortress in the foothills north of Cusco, historic capital of the Inca Empire, in today's Peru. The Killke culture started the fortress in the early twelfth century and the Incas expanded it starting in the thirteenth century. The dry stone walls are made of huge stones that are cut so precisely that they fit together without mortar.. Learn more.