Sumidero Canyon National Park, National park and natural canyon in Chiapas, Mexico

Sumidero Canyon National Park follows the Grijalva River in Chiapas, with limestone walls rising over 1,000 metres. The 21,789-hectare park spans five municipalities, including Tuxtla Gutiérrez and Chiapa de Corzo. Its tropical deciduous forest shelters the endemic Agave grijalvensis.

The canyon began forming about 70 million years ago through tectonic movements known as horst-graben, which raised the limestone walls. The limestone itself started forming around 136 million years ago from marine sediments and coral. The area was declared a national park on 8 December 1980 and a Ramsar site on 2 February 2004.

The park received federal protection status in 1980 to preserve its geological formations, maintain scientific research opportunities, and protect the local wildlife populations.

Boat tours depart from Chiapa de Corzo and pass through the gorge, where visitors can see river turtles and crocodiles. The trips run year-round and offer views of the high rock walls.

The canyon walls are limestone laid down about 136 million years ago from marine sediments and coral, meaning this part of Chiapas was once a shallow sea. The Grijalva cuts roughly 30 km through the gorge before reaching the Chicoasén dam. Five viewpoints line the rim: La Ceiba, La Coyota, El Roblar, El Tepehuaje and Los Chiapa.