For travelers, the valley’s main attractions have long been two fascinating and well-excavated Maya ruins: Bonampak , home to a stunning set of thousand-year-old fresco paintings; and Yaxchilán , a grand city rising dramatically from the banks of the Río Usumacinta, along which you are sure to spot crocodiles and howler monkeys in the trees.
Not long ago, the only way to visit the ruins was by a rutted one-track road, followed by a long hike through the rainforest. Nowadays, a paved highway—the Carretera Fronteriza , or Border Highway—and reliable boat service make visiting Bonampak and Yaxchilán easy and secure, whether by tour or on your own. (Roadside robberies, once a problem, are now quite rare, especially in daylight hours.)
That’s not to say there aren’t out-of-the-way places to visit. The still-traditional Lacandón villages of Nahá  and Metzabok  are nestled in forest reserves, 40-plus kilometers down a rough dirt road. Both have simple accommodations and terrific boating and hiking. Easier to reach, but no less impressive, is Plan de Ayutla Archaeological Zone , a partially excavated and rarely visited ruin outside the town of Nueva Palestina .
Greater accessibility has been less kind, or perhaps too kind, to the Lacandón village of Lacanjá Chansayab . Just a few kilometers from Bonampak ruins, the village has been given over almost entirely to mass tourism, at the cost of much of the community’s traditional customs and independence.