A panoramic road from Tuxtla Gutiérrez runs above the Río Grijalva framed by the high walls of the Cañon del Sumidero - reaching as high as 1,000m. It is dotted with several viewpoints affording magnificent vistas, the most spectacular being the mirador Los Chiapas, a must-see. But a boat ride here is an even more unforgettable experience. Sitting in a lancha, you sail down the river lined by numerous caves and peopled by an abundance of riverbank wildlife including crocodiles, spider monkeys and egrets.