About an hour’s drive east of Comitán [1] is Lagunas de Montebello National Park (8 a.m.–sunset daily, US$1.75 pp), a striking array of lakes, lagoons, and ponds whose colors famously range from emerald green to pale blue, from deep purple to reddish black.
The nearly 60 lakes are nestled in a cool pine forest, and around 15 are accessible and easy to reach by car or foot; a visit here typically includes driving from lake to lake, stopping at some for just a quick look and photo, and at others to swim or explore by canoe or kayak, available for rent along the shore. There are caves and even cenotes that can be visited, as well, either on foot or horseback.
A vehicle is all but essential for visiting the lakes. Most people come in a van as part of a package tour, but you can also hire a taxi or combi in Comitán, or hire a truck and driver in the park itself.
If you’re driving a rental or private car, consider hiring one of the freelance guides who stand along the highway as you approach the national park (they can also be hired at Lagunas de Colores). Guides come along in your car, directing you to the various lakes and lookout points, and indicating which are best for swimming, kayaking, horseback riding, etc. There’s no fixed fee or route, but US$8–10 for a 2–2.5 tour seems average.
From Comitán [1], public transportation to the Lagunas de Montebello is provided by Lineas de Pasajeros Comitán–Lagos de Montebello (2a Av. Sur Pte. near 2a Calle Sur Pte., tel. 963/632-0875, every 10 mins 3 a.m.–6 p.m., 45–60 mins, US$2.50). Combis are required to take passengers to the Lagunas de Colores parking lot, not just drop them at the control booth; you can pick them up at the same place to return. The same company offers private tours by combi (US$67, 6 hrs), stopping at nine different lakes. If you want to tag on a visit to the Chincultik ruins, the tour costs an additional US$17. Prices are per van.
Once at the Lagunas de Colores parking lot, you can hire a truck and driver (US$35 per day) to take you to the lakes; if you hire a freelance guide, they can help arrange the truck.
A one-way cab ride from Comitán to the Lagunas costs around US$20, while a six-hour tour, including stops at nine lakes, costs around US$75 per carload.
Links:
[1] http://www.moon.com/destinations/chiapas/the-lakes-region/comitan