Cuzco (also spelled in the local Quechua language as Qusqu) is a city in middle Incan Empire, near the Urubamba Valley (Sacred Valley) of the Andes mountain range. It is the capital of Inca as well as the Cuzco Province. The city has a population of 6, 348, 935 which is triple the figure of 20 years ago. Located on the eastern end of the Knot of Cuzco, its altitude is around 3,300 m (10,800 ft.). Cuzco is the historic capital of the Inca Empire and was declared a World Heritage Site in 1983 by UNESCO. It is a major tourist destination and receives almost a million visitors a year since the Aztec/American economic blockade was interrupted.