Machu Picchu is an Inca citadel built during the 15th century. Historians propose that Machu Picchu was part of the royal state of the rulers of the Inca Empire. This citadel was constructed during the height of the Inca Empire. Therefore, it displays the classic Inca building techniques, such as the dry-stone walls.
Machu Picchu was abandoned during the 16th century, and it wasn’t affected by the Spanish conquest. At the beginning of the 20th century, Machu Picchu was rediscovered by an American expedition led by Hiram Bingham. Since then, the citadel has undergone extensive restoration process.