The largest lake in the Lacandón rainforest (16 square kilometers), and one of the cleanest and purest bodies of water anywhere in Mexico, Laguna Miramar (Reserva Integral de la Biósfera Montes Azules) truly is a jewel of Chiapas and the whole country. In fact, from the air, that’s exactly that it looks like: a radiant blue gemstone in a vast blanket of green forest, its deep indigo center fading to a lovely aquamarine at the edges. Its name, Spanish for “view of the sea,” is surprisingly apt for a lake that’s hundreds of kilometers from the nearest ocean.

Laguna Miramar owes its pristine state to an agreement among the surrounding communities to ban virtually all development within a kilometer of the lake, and to prohibit the use of motorboats. With no chemicals or waste from roads, hotels, farmland, or leaky boat engines, Miramar’s water is crystal clear, and you can see the bottom a dozen meters or more down. It also happens to be bathtub warm, perfect for swimming.

Getting to Laguna Miramar

By Bus: The traditional way to get to Laguna Miramar is by bus, a bone-jarring six-to-seven-hour journey from Ocosingo to the small town of San Quintín (US$6, 4 departures daily). From there, it’s a 15-minute walk to Emiliano Zapata, past an imposing Mexican military base established here following the Zapatista uprising in 1994.

By Boat: A more scenic and far less punishing route is by boat, approaching from the south along the Río Jataté. Lanchas (motorboats) leave from the community of La Democracia, winding two hours through increasingly pristine rainforest to arrive right at Emiliano Zapata (US$70 each way, up to six people); any number of local boatmen can take you, though boat operator Hipólito Vásquez is recommended for having life vests aboard. Be sure to arrange for a pickup, unless you plan to leave by bus. Be aware that partway up the river you will be required to pay a passage fee to Zapatista militants who control that section of the forest, around US$10 per boat.

From Comitán, Transportador Tzobol (4a Av. Pte. Sur, tel. 963/632-7739) has direct service to the town of Amatitlán (US$5.50, 3.5 hrs, 4 a.m., 5 a.m., 8 a.m., noon and 1 p.m.), located just across the river from La Democracía and connected by a bridge. Otherwise take any combi to the town of Maravilla Tenejapa, and transfer to an Amatitlán combi there (US$2, 40 mins).

By Car: If you’re driving, look for a turnoff marked Guadalupe Miramar, a few kilometers east of Maravilla Tenejapa on the Carretera Fronteriza. From there, a dirt road winds through a number of small communities to Amatitlán, with La Democracía just across the bridge.

By Air: Chiapas has few vistas more stunning than Laguna Miramar from the air. Servicios Aéreos San Cristóbal (Aérodromo Miguel Alemán, Carr. Comitán–Trinitaria Km. 1262, tel. 963/632-4662, toll-free Mex. tel. 800/523-4954, www.serviciosaereossancristobal.com) offers scenic flyovers of Laguna Miramar (US$500, 90 mins, including Lagunas de Montebello and Las Nubes), as well as drop-off/pickup service (US$250 per leg), using four-passenger Cessna single-engine planes, departing from its base in Comitán.