Machu Picchu, located in the Cusco Region of Peru, was voted as one of the New Seven Wonders of the World in 2007. The New Seven Wonders of the World were chosen by more than 100 million people from all over the world through an open online vote. Machu Picchu is a 15th-century Inca citadel situated on a mountain ridge 2,430 meters (7,970 ft) above sea level. It was built in the classical Inca style, with polished dry-stone walls, and its three primary structures are the Inti Watana, the Temple of the Sun, and the Room of the Three Windows. Most archaeologists believe that Machu Picchu was built as an estate for the Inca emperor Pachacuti (1438–1472). The Incas built the estate around 1450 but abandoned it a century later at the time of the Spanish Conquest. Machu Picchu was declared a Peruvian Historical Sanctuary in 1981 and a UNESCO World Heritage Site in 1983.