In the days when Tenochtitlan was the island capital of the Aztecs, the city was linked to Chapultepec by a causeway and the hill was a retreat for the Emperors. A sculpture of Moctezuma I can still be seen (in unfortunately damaged condition) carved into the rock of Chapultepec, not far from Huemac's cave.
After Mexico won its independence, the old viceregal palace was turned into a military accademy in 1833. During the Mexican American War a group of young teenaged cadets fought to their deaths against the invading United States Army here; they are remembered as the "Boy Heroes" of Mexico. (see: Battle of Chapultepec)
Chapultepec Park Today
The hill of Chapultepec and surrounding land are now Chapultepec Park, a popular spot both for locals and tourists. Chapultepec is at one end of the city's grandest avenue, Paseo de la Reforma.
The park covers 1,600 acres of land, centuries old forest, several small lakes, and landscaped areas with out-door cafes.
The Castle atop the hill is a history museum. The park also includes 6 other museums, including a museum of modern art and the very large National Museum of Anthropology with perhaps the world's finest collection of Pre-Columbian Mesoamerican art and artifacts.