The Lacandon Jungle is an area of rainforest which stretches from Chiapas, Mexico, into Guatemala. The heart of this rainforest is located in the Montes Azules Biosphere Reserve in Chiapas near the border with Guatemala in the Montañas del Oriente region of the state. Although much of the jungle outside the reserve has been cleared, the Lacandon is still one of the largest montane rainforests in Mexico. It contains 1,500 tree species, 33% of all Mexican bird species, 25% of all Mexican animal species, 56% of all Mexican diurnal butterflies and 16% of all Mexico's fish species.

Chiapas, officially the Free and Sovereign State of Chiapas, is one of the states that make up the 32 federal entities of Mexico. It comprises 124 municipalities as of September 2017 and its capital and largest city is Tuxtla Gutiérrez. Other important population centers in Chiapas include Ocosingo, Tapachula, San Cristóbal de las Casas, Comitán, and Arriaga. Chiapas is the southernmost state in Mexico, and it borders the states of Oaxaca to the west, Veracruz to the northwest, and Tabasco to the north, and the Petén, Quiché, Huehuetenango, and San Marcos departments of Guatemala to the east and southeast. Chiapas has a significant coastline on the Pacific Ocean to the southwest.