Chichen Itza was a large Mayan city on the Yucatan Peninsula of Mexico. The city was established in the early 400's AD and was inhabited until 900 AD. At its height, it is believed that as many as 50,000 people lived in the city. After the Spanish conquest of the Yucatan in 1547, many of the abandoned city's structures received Spanish names. The city was later forgotten and covered by jungle. The city was rediscovered in the 1840's. This is the Platform of Eagles and Jaguars, a square platform with carved side panels of eagles and jaguars eating human hearts. On each side are staircases topped with large heads of feathered serpents.