Chapultepec, more commonly called the "Bosque de Chapultepec" (Chapultepec Forest) in Mexico City, is one of the largest city parks in Mexico, measuring in total just over . 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 park, became the presidential residence.
Bosque de Chapultepec is divided into four sections, with the first section being the oldest and most visited. This section contains most of the park's attractions, including the castle, the Chapultepec Zoo, the Museum of Anthropology, and the Rufino Tamayo Museum, among others. It receives an estimated 15 million visitors per year. This prompted the need for major rehabilitation efforts that began in 2005 and ended in 2010. The government has authorized the construction of business, offices, and big parking lots for cars.
According to studies, there has been human presence in the area since at least the pre-Classic period. The first identified culture archaeologists have evidence for is the Toltecs. The Toltecs named the area "grasshopper hill", which would later become Nahuatl "Chapoltepēc" ("at the grasshopper hill"). Remains of a Toltec altar have been found on the hill's summit. In the Classic Period, the area was occupied by people of the Teotihuacan culture. When the Mexicans, or Aztecs arrived in the Valley of Mexico, it was inhabited by a people called the Tepanecas of Azcapotzalco.
When the Aztecs took over the Valley of Mexico, they considered the hill as both a sacred and strategic site.