Sacsayhuaman National Archaeological Park

Sacsayhuamán, often spelled Saqsaywaman or Xacxaguaman,, is a citadel on the northern outskirts of the city of Cusco, Peru, the historic capital of the Inca Empire. The site is at an altitude of 3,701 m.

The complex was built by the Incas in the 15th century, particularly under Sapa Inca Pachacuti and his successors. Dry stone walls constructed of huge stones were built on the site, with the workers carefully cutting the boulders to fit them together tightly without mortar.

In 1983, Cusco and Sacsayhuamán together were designated as sites on the UNESCO World Heritage List, for international recognition and protection. The site is now constantly explored by tourists.

Source: Wikipedia