Chapultepec Castle (Spanish: Castillo de Chapultepec) is located on top of Chapultepec Hill in Mexico City's Chapultepec park. The name Chapultepec is the Nahuatl word chapoltepēc which means "at the grasshopper's hill". The castle has such unparalleled views and terraces that explorer James F. Elton wrote that they can't "be surpassed in beauty in any part of the world." It is located at the entrance to Chapultepec Park at a height of 2,325 meters 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 that of Military Academy, Imperial residence, Presidential residence, observatory, and since the 1940s, the National Museum of History. Chapultepec, along with Iturbide Palace, are the only royal palaces in North America.It was built during the Viceroyalty as summer house for the highest colonial administrator, the viceroy. It was given various uses, from the gunpowder warehouse to the military academy in 1841. It became the official residence of Emperor Maximilian I and his consort Empress Carlota during the Second Mexican Empire (1864–67). In 1882, President Manuel González declared it the official residence of the President. With few exceptions, all succeeding presidents lived there until 1939, when President Lázaro Cárdenas turned it into a museum.