Palenque the ruin is the reason to come, and it rewards being there at opening time: the site sits against the first hills of the Chiapas highlands with jungle pressing in on three sides, howler monkeys audible before anything is visible, and mist in the trees until the sun burns it off. Only a fraction of the city has been excavated; the rest is under the forest you are looking at.
The waterfalls west of town — Agua Azul, a long staircase of blue limestone pools, and Misol-Ha, a single thirty-five-metre drop you can walk behind — are sold as a combined day with Palenque itself. Agua Azul runs brown rather than blue after heavy rain, which is most afternoons in the wet season.
Deeper in, on the Usumacinta river that marks the Guatemalan border, Bonampak has the best-preserved Maya murals known — a painted record of a court, a battle and its aftermath — and Yaxchilán can only be reached by boat upriver from Frontera Corozal. Both are long days from Palenque and longer ones from San Cristóbal.