Cuzco, often spelled Cusco, is a city in southeastern Peru, near the Urubamba Valley of the Andes mountain range. It is the capital of the Cusco Region as well as the Cusco Province. In 2013, the city had a population of 435,114. Located on the eastern end of the Knot of Cuzco, its elevation is around 3,400 m. The site was the historic capital of the Inca Empire from the 13th until the 16th-century Spanish conquest. In 1983 Cusco was declared a World Heritage Site by UNESCO.