Chapultepec Castle is located on top of Chapultepec Hill in Mexico City's Chapultepec park. The name Chapultepec is the Nahuatl word chapoltepēc which means "on the hill of the grasshopper". It is located at the entrance to Chapultepec park, at a height of 2,325 metres (7,628 ft) above sea level. The site of the hill was a sacred place for Aztecs, and the buildings atop it have served several purposes during its history, including serving as a military academy, imperial residence, presidential residence, observatory, and since February 1939, the National Museum of History. Chapultepec Castle, along with Iturbide Palace, also in Mexico City, are the only royal palaces in North America which were inhabited by monarchs.