The Sumidero Canyon is a crack in the Chiapas highlands with the Grijalva river at the bottom, and its walls run up to about a kilometre in places. Most visitors see it from a boat that leaves Chiapa de Corzo, but a rider gets the other view, from the rim road that climbs out of Tuxtla and visits a string of lookouts along the edge. Each has its own name, its own car park and its own stall selling fruit and sweets, and each shows the same trench from a different angle: vertical rock, green water, and a ribbon of foam far below. The water is a lake now, held back by the Chicoasén dam, finished in 1980, so the canyon is a flooded canyon, though it is no less dramatic for that.
The riding to get to it is short and simple. The road leaves Tuxtla, the state capital, and rises through dry forest and farmland to the national park gate, with a decent surface, wide bends and ample room for a rider to look about. Traffic is light on weekdays. At the miradores the ground is rough and the edges are often barely fenced, so watch your feet, and keep your helmet on when you walk to the rail. The heat is heavy by late morning, and the haze can wash out the photographs, so the first hours of the day serve you best.
There is a story people tell here, though how much of it is history and how much memory is hard to say. When the Spaniards came in the 1520s, the Chiapa warriors are said to have chosen to throw themselves into the gorge rather than surrender, and the canyon has carried that dark pride ever since. Crocodiles still sun themselves on the banks, spider monkeys cross the canopy, and vultures ride the thermals at eye level from the lookouts.
Fuel and food are easy in Tuxtla, a city of half a million, twelve kilometres from the park gate, so fill up before you climb. At the rim you will find cheap snacks, fresh fruit with chilli and lime, and drinks. Bring your own water all the same, because the sun is fierce, and there is little shade at most of the lookouts.