Sacsayhuamán, a large Inca fortress overlooking Cuzco, Peru; from a hilltop 230m above the city. It was built in 15th Century AD, during reign of Pachacuti Inca Yupanqui.
Built with stones that were up to more than 8.2m tall and weighed many tons, and with zigzag walls more than 305m in length, Sacsayhuamán is a feat of human engineering, the story of whose construction has caused much discussion among archaeologists. In construction of Sacsayhuamán, stones were laid together without the use of mortar, and they seem to be immovable by nature. Although earthquakes have laid waste to many more modern buildings in the locality, Inca site itself has remained unshaken by any of tremors. The purpose for which Sacsayhuamán was built is uncertain. The walls and original towers seem clearly defensive in nature. The site also incorporates a large plaza surrounded by terraces, and it is thought that this area may have been used for ceremonies. In addition, it is thought that there were temples in complex. In 2008, archaeologists uncovered the ruins of a pre-Inca temple and roadway at site’s periphery.