The state has thirty-six protected areas at the state and federal levels along with 67 areas protected by various municipalities. The Sumidero Canyon National Park was decreed in 1980 with an extension of . It extends over two of the regions of the state, the Central Depression and the Central Highlands over the municipalities of Tuxtla Gutiérrez, Nuevo Usumacinta, Chiapa de Corzo and San Fernando. The canyon has steep and vertical sides that rise to up to 1000 meters from the river below with mostly tropical rainforest but some areas with xerophile vegetation such as cactus can be found. The river below, which has cut the canyon over the course of twelve million years, is called the Grijalva. The canyon is emblematic for the state as it is featured in the state seal. The Sumidero Canyon was once the site of a battle between the Spaniards and Chiapanecan Indians. Many Chiapanecans chose to throw themselves from the high edges of the canyon rather than be defeated by Spanish forces. Today, the canyon is a popular destination for ecotourism. Visitors can take boat trips down the river that runs through the canyon and see the area's many birds and abundant vegetation.