The Third Section is located on the west side of the second and was inaugurated in 1974. It has a surface of 243.90 hectares of which 137.71 are ravines. In 1992 it was declared a Natural Protected Area. This section is the least-accessible and visited area of the park. the importance of this area is primarily as an ecological preserve for various species of flora and fauna. It has an estimated 85,550 trees among which eucalyptus and pine predominate.

Mexico´s City Department of the Environment reported that as part of the Chapultepec Forest, Nature and Culture project, an environmental restoration is being executed in this section.

Among the actions implemented is rehabilitation of the Seed Library, the socialization campaign in the Tacubaya ravine, the design of the project for the treatment of solid waste in the Dolores Civil Cemetery, the integration of the Environmental Master Plan, among others.

To keep the population informed about the regeneration and improvement actions, kiosks were placed where more than 15,416 people were attended. In addition, a website was created that has received 34 thousand 58 visits, and more than 800 meetings have been held with neighbors, merchants, artists and people who use the park. Learn more about this project at https://www.procesodeconsultachapultepec.mx/acciones