Machu Picchu (AKA "Lost City of the Incas") is a well-preserved pre-Columbian Inca ruin situated above the Urubamba Valley in Peru on a high mountain ridge. Altitude ranges from Ranges from 1,800m to 3,800m. Machu Picchu, now the most familiar symbol of the Inca Empire, had been forgotten for centuries by the outside world and was brought back to international attention by Yale archeologist Hiram Bingham who rediscovered it in 1911. Peru is pursuing legal efforts to get back thousands of artifacts that Bingham removed from the site. Today it is one of the most important archaeological centres in South America and as a consequence the most visited tourist attraction in Peru. The city was built by the Sapa Inca Pachacuti. Construction starting in about 1440, and was inhabited until the Spanish conquest of Peru in 1532. The incans called it a "llacta": a settlement build up to control the economy of the conquered regions. It was the most beautiful llacta of the Incan empire and would have been built with the specific purpose of protecting the most select of the Incan aristocracy in the event of an attack. The site has a large palace and temples to Inca deities around a courtyard, with other buildings for support staff. It is estimated that a maximum of only about 750 people resided in Machu Picchu at any one time, and probably only a small fraction of that number lived in the town during the rainy season and when none of the nobility were visiting. Machu Picchu is divided in three great sectors: the Sacred District, the Popular District and the District of the Priests and the Nobility (royalty zone). The royalty area consisted of a group of houses located in rows over a slope ocupied by the Amautas (wise persons) (houses with reddish walls) and Ñustas (princesses) (houses with trapezoid-shaped rooms).The sacred district contained the Intiwatana, the Temple of the Sun and the Room of the Three Windows. These were dedicated to Inti, their sun god and greatest deity.