Chapultepec Section 1 is far and away the most visited part of the Chapultepec Forest. Importantly, some of the sites included in our list of Chapultepec Reforma are not technically in the park at all. They still make up a good part of the experience of the park.
The Bosque de Chapultepec is centered on the rock formation called Chapultepec Hill, that had become a retreat even for Aztec rulers. Later, during the late-colonial period, the Chapultepec Castle took shape here and served as the official residence of Mexican presidents until 1940. After that, Mexican Presidents went to another part of the park called Los Pinos, a whole story unto itself.
The castle is simply surrounded by museums, monuments, fountains and other sites of interest. Those in the map make up not just Chapultepec Section 1, but the magnificent heart of Chapultepec and Mexico City. There's a story to each of them, some old, some new.