Just a few hours south of Cancún's clutter of hotels sprawls one of Mexico's most pristine ecological parks. The 1.3-million acre Sian Ka'an Biosphere Reserve represents the greatest diversity of habitats in the Yucatán Peninsula, with equal parts tropical forests, wetlands, bays, and marine areas.
Few travelers journey to this far bottom edge of the Riviera Maya. Those who do find an oasis from the heavily touristed corridor: Sian Ka'an's endless horizon leaves a lasting impression, living up to its translation, Where the Sky Is Born.
The park reaches about 30 miles inland from the sea and is close to 75 miles long. Its name was actually given by the fifth-century Maya to the entire southern portion of the state Quintana Roo.
Within its expanse exist more than 100 species of mammals and about 350 species of birds. Aquatic life is also abundant in Sian Ka'an.
Aside from its natural attractions, this UNESCO World Heritage site is known for its 23 Mayan archaeological sites.
The Mexican government declared Sian Ka'an a protected area in 1986. The goal is to preserve the flora, fauna, and ecosystems of the area while satisfying the needs of the local population, according to Amigos de Sian Ka'an.
This nonprofit group is one of the key organizations involved in the careful development of the reserve, as well as the education of the natives who live in the communities inside the reserve in horticulture, lobster management, diversification of fisheries, and eco-tourism.
Eco-tourism is not just a catchphrase at Sian Ka'an. Only about 15 percent of the reserve is open to visitors, mainly along the coast. Within those areas, there are a number of rules prohibiting overdevelopment - piers on poles to avoid erosion, no new access roads, no sand extraction, and no lights eastward on sea turtle breeding areas.
The result of the regulations has been positive for the environment, according to Alfredo Arellano Guillermo, who has been director of Sian Ka'an for the past eight years. "We have very good conditions in all of the ecosystems."
This is confirmed, he says, by frequent sightings of jaguars, tapirs, dolphins, manatees, leatherback sea turtles, and numerous species of birds.
Tourism has been an economic savior of sorts for the local Sian Ka'an population, which today numbers about 1,000. About 160 of them have trained as guides. Some studied natural history to help lead visitors along the nature trails in the park, others ornithology, and others English.
Most of the tourist facilities are centered at Punta Allen, where popular activities include boating and kayaking. The town, which offers restaurants and lodging, is also a base for exploring the park.
Other tourist centers are in more isolated Punta Herrero and Muyil, where important bird populations draw visitors.
Tour operators from outside the park run day trips from Cancún and enlist the services of the local tour guides who are required within the park boundaries.
The variety of tour options is vast. Popular trips from the Riviera Maya include a jeep safari along the bumpy, unpaved road to Punta Allen. Often a day trip will also include a boat trip in Ascensión Bay for bird-watching, as well as viewing sea turtles and dolphins. It's possible to snorkel among the reefs, as well.
Bird-watchers can also sign up for a boat trip through the wetlands, in the hopes of viewing aquatic birds such as white ibises, roseate spoonbills, the rare jabiru stork, wood storks, flamingos, egrets, or one of the park's 15 species of heron. Two local nonprofit groups, Amigos de Sian Ka'an and Centro Ecologico Akumal, can arrange tours of the waterways and Mayan canal systems inside the reserve.
Sian Ka'an is also a haven for kayakers, who ply the waters of the mangrove forest and freshwater lagoons, where manatees make their home. Hidden between the massive mangrove roots live oysters, sponges, sea squirts, hydroids, sea anemones, and crustaceans.
The mangroves also provide an ideal nesting spot for water birds such as roseate spoonbills, reddish egrets, brown pelicans, white pelicans, fish crows, and herons. Sometimes tapirs, deer, ocelots, jaguars, panthers, and tamanduas can be spotted in the outlying areas.
Many sport fishermen come for the tarpon, snook, and bonefish. More than 95 percent of the fish captured by fly fishermen are released. The fishing-tour operators also regulate the speed of boats and know where it is safe to anchor in order to avoid damage to the coral reefs.
Some tours beyond the borders of the reserve incorporate the Mayan ruins at Muyil, which was a vital link for the ancient maritime trade route along the coast of Quintana Roo. Artifacts from Guatemala and Honduras have been found at Muyil.
Studies show that Mayan groups began to inhabit the site around 300 BC, long before the renowned ancient Mayan cities of Tulum or Chichén Itzá were founded.
Many of the buildings at Muyil have been restored. One of the main attractions is El Castillo, (the Castle), which, at 55 feet, is taller than any of the buildings in Tulum or at other sites along the coast.
The Maya excavated the canals by hand to link Boca Paila, on the sea, to Laguna Chunyaxche and Laguna Muyil, where the ruins are located.
Today, boats take tourists through the lakes and canals used in that route, some heading all the way to Boca Paila and the bays, where there are large populations of birds.
Planeta Maya Tours, which runs one-week trips based outside the park at the village of Wak Nabal, also takes visitors on day outings for kayaking as well as to visit the park's cenotes, underground rivers (now sinkholes) where Mayan gods were believed to have purified their souls.
EcoColors offers a nine-day eco-tour to a cenote where wild crocodiles live and nest. From May through September, the company also offers night trekking to view sea turtles laying eggs.
The easiest way to see Sian Ka'an is by taking a tour (see box). But it's possible to drive if you have a four-wheel-drive vehicle that can stand up to the bumpy dirt road. There is no charge to enter the park; simply register your car at the entrance. The last real gas station is in Tulum.
Adventurous travelers may also visit the ruins at Muyil on their own. It is about 10 miles south of Tulum on Federal Highway 307. By car it is 90 miles south of Cancún.
The best way to experience Sian Ka'an is to take a tour. Tour groups that visit the area include:
Amigos de Sian Ka'an, www.cancun.com/siankaan.
Centro Ecologico Akumal, http://ceakumal.org.
Bonefish Bum, www.worldwidefishing.com/ mexico/b2028.
[Editor's note: One additional information link was removed from the original version because the URL now links to pornographic content.]