Chapultepec, more commonly called the "Bosque de Chapultepec" (Chapultepec Forest) in Mexico City, is one of the largest Nature Value Areas in Mexico, measuring in total just over 866 hectares (2,140 acres). Centered on a rock formation called Chapultepec Hill, one of the park's main functions is as an ecological space in Greater Mexico City. It is considered the first and most important of Mexico City's "lungs".
The area encompassing modern-day Chapultepec has been inhabited and considered a landmark since the pre-Columbian era, when it became a retreat for Aztec rulers. In the colonial period, Chapultepec Castle was built here, eventually becoming the official residence of Mexico's heads of state. It would remain so until 1934, when Los Pinos, in another area of the forest, became the presidential residence.