There’s no mistaking the Río Tulijá, a ribbon of luminescent turquoise water wending through farmland and dense tropical forest and visible from parts of Highway 199 between Palenque and Ocosingo. Known to local Maya as Yaks-Ha (Blue Water), the river was described by Chiapanecan poet Elva Macías as “a peacock dragging its watery tail,” and you’d be forgiven if at first glance you thought it was the result of contamination or a mineral dissolved in the water.

In fact, the water is not only clean but perfectly transparent, and the unusual color is the result of sunlight reflecting off the limestone riverbed. (For that reason, the effect isn’t visible all year; during rainy season—roughly August to January—sediment washes into the river and turns the water a turbid brown.)

There are three popular and impressive sites along the Río Tulijá: Misol-Há (a high beautiful waterfall), Agua Clara (a large picturesque pool), and Agua Azul (a series of powerful waterfalls). All three are reached by way of access roads (3–5 km long) that are well-marked on Highway 199.

Tour operators in Palenque offer popular and affordable tours, either stopping at all three or just Misol-Há and Agua Azul. The trips typically include a half hour at Misol-Há and Agua Clara (if included) then three hours at Agua Azul. You can also visit them independently, preferably by car, as there’s little public transport along the access roads.

At the time of research, members of the local ejidos (land cooperatives, ostensibly affiliated with the Zapatistas in this case) had set up road blocks at Agua Clara and Agua Azul, and were charging US$5 per vehicle to pass. Agua Azul remained open as normal, but Agua Clara was shut down while the situation was negotiated. Ask tour operators in Palenque for the latest.