4 Best Sights in Yucatán and Campeche States, Mexico

Encompassing some 1.8 million acres along the Guatemalan border, Calakmul was declared a protected biosphere reserve in 1989 and is the largest of its kind in Mexico (Sian Ka'an in Quintana Roo is second with 1.3 million acres). All kinds of flora and fauna thrive here, including wildcats, spider and howler monkeys, hundreds of exotic birds, orchid varieties, butterflies, and reptiles. There's no shortage of insects, either, so don't forget the bug repellent.

The reserve's centerpiece, however, is the Maya city that shares the name Calakmul (which translates as "two adjacent towers"). Although Carretera 186 runs right through the reserve, you'll need to drive about 1½ hours from the highway along a 60-km (37-mile) authorized entry road to get to the site. Structures here are still being excavated, but fortunately the dense surrounding jungle is being left in its natural state: as you walk among the ruined palaces and tumbled stelae, you'll hear the guttural calls of howler monkeys and see massive strangler figs enveloping equally massive trees.

Anthropologists estimate that in its heyday (between AD 542 and 695) the region was inhabited by more than 50,000 Maya. Archaeologists have mapped more than 6,800 structures and found 180 stelae. Perhaps the most monumental discovery thus far has been the remains of royal ruler Gran Garra de Jaguar (Great Jaguar Claw). His body was wrapped (but not embalmed) in a shroud of palm leaf, lime, and fine cloth, and locked away in a royal tomb in about AD 700. In an adjacent crypt, a young woman wearing fine jewelry and an elaborately painted wood-and-stucco headdress was entombed together with a child. Their identity remains a mystery. The artifacts and skeletal remains have been moved to the Museo de la Arqueología Maya in Campeche City.

You can explore the site along a short, medium, or long path, but all three eventually lead to magnificent Templo II and Templo VII—twin pyramids separated by an immense plaza. Templo II, at 175 feet, is the peninsula's tallest Maya building. Scientists are studying a huge, intact stucco frieze deep within this structure, so it's not currently open to visitors.

Arrangements for an English-speaking tour guide should be made beforehand with Servidores Turísticos Calakmul, Río Bec Dreams, or through Chicanná Ecovillage near Xpujil. Camping is permitted at Km 6 with the Servidores Turistícos Calakmul after paying caretakers at the entrance gate. You can set up camp near the second checkpoint. Even if day-tripping, though, you'll need to bring your own food and water, as the only place to buy a snack is near the second entrance inside the museum. In addition to separate fees to enter the reserve and the archaeological site, you'll also pay MX$42 per person and MX$70 per vehicle to access the first 20 km (12½ miles) of road into the reserve, which runs through private land.

Celestún is the point of entry to the Reserva de la Biósfera Ría Celestún, a 146,000-acre wildlife reserve with extensive mangrove forests and one of the largest colonies of flamingos in North America. Clouds of the pink birds soar above the estuary all year, but the best months for seeing them in abundance are November through March. This is also the fourth-largest wintering ground for ducks of the Gulf-coast region, and more than 365 other species of birds, plus a large sea-turtle population, make their home here. Mexican and American conservation programs protect the birds, as well as the endangered hawksbill and loggerhead marine tortoises, and species such as the blue crab and crocodile. Other endangered species that inhabit the area are the ocelot, the jaguar, and the spider monkey.

The park is set among rocks, islets, and white-sand beaches. There's good fishing here, too, and several cenotes that are wonderful for swimming. Most Mérida travel agencies run boat tours of the ría (estuary) in the early morning or late afternoon, but it's not usually necessary to make a reservation in advance.

To see the birds, hire a fishing boat at the entrance to town (they hang out under the bridge leading into Celestún). A 75-minute tour for up to six people costs about MX$1,200; a two-hour tour costs around MX$2,500. Although more expensive (MX$990 per person), local tour expert Alex specializes in ecotours and donates a portion of the proceeds to the Celestún Conservation Program (call Hotel Eco Paraíso to book).

Popular with Mexican vacationers, the park's sandy beach is pleasant during the morning but tends to get windy in the afternoon. And, unfortunately, mosquitoes gather in great numbers on the beach at dawn and dusk, particularly during winter months, making a walk on the beach uncomfortable. Most hotels offer mosquito netting around the beds, but bring along a good cream or spray to keep the bugs away.

Celestún is the point of entry to this 146,000-acre wildlife reserve with extensive mangrove forests and one of North America's largest flamingo colonies. Clouds of the pink birds soar above the estuary all year, but the best months for seeing them in abundance are November through March. This is also the fourth-largest wintering ground for ducks of the Gulf coastal region, and more than 365 other bird species make their home here, as do sea turtles. Mexican and American conservation programs protect the birds, as well as the endangered hawksbill and loggerhead marine tortoises, and species such as the blue crab and crocodile. Other endangered species that inhabit the area are the ocelot, the jaguar, and the spider monkey.

The park, which is set among rocks, islets, and white-sand beaches has several cenotes that are wonderful for swimming. The fishing is good here, too. Popular with Mexican vacationers, the park's sandy beach is pleasant during the morning but tends to get windy in the afternoon. And, unfortunately, mosquitoes gather in great numbers on the beach at dawn and dusk, particularly during winter months, making a walk on the beach uncomfortable. Area hotels generally drape their beds with mosquito netting, but bring along a good cream or spray to keep the bugs away.

Most Mérida tour operators run boat excursions of the ría (estuary) in the early morning or late afternoon, and it's not usually necessary to make a reservation in advance. Alternatively, you can hire a fishing boat at the entrance to town (they hang out under the bridge leading into Celestún). A 75-minute tour for up to six people costs about MX$1,200; a two-hour tour costs around MX$2,500. Although more expensive (MX$990 per person), local expert Alex specializes in ecotours and donates a portion of the proceeds to the Celestún Conservation Program (call Hotel Eco Paraíso to book).

This reserve which encompasses a long estuary, was developed with ecotourism in mind—although few of the crocodiles for which it and the village were named remain. The real spectacle is provided by birds. April through September, thousands of the bright pink, black-tipped flamingos—90% of the Western Hemisphere's entire flamingo population—come to here from their "summer homes" in Celestún, on the Yucatán's west coast, as well as from northern latitudes to mate, nest, and raise their chicks. The largest flock of bird-watching enthusiasts also descends on the reserve during this time.

Although the long-legged pink creatures are the most famous winged beasts found in Ría Lagartos, its red, white, black, and buttonwood mangrove swamps are also home to hundreds of other birds, including including snowy and red egrets, white ibis, great white herons, cormorants, pelicans, and peregrine falcons. Of the reserve's estimated 380 different species, one-third are winter-only residents. Twelve of the region's resident species are found nowhere else on Earth.

In addition, protected leatherback, hawksbill, and green turtles lay their eggs on the beaches at night. The fishing is good here, too. Mosquitoes can gather at dusk in unpleasantly large swarms in May, June, and July. Bring repellent to fend them off.