Travelers to the peninsula have an opportunity to see pre-Hispanic ruins -- such as Chichén Itzá, Uxmal, and Tulum -- and the living descendants of the cultures that built them, as well as the ultimate in resort Mexico: Cancún. The Yucatán peninsula borders the aquamarine Gulf of Mexico on the west and north, and the clear blue Caribbean Sea on the east. It covers almost 134,400 sq. km (51,892 sq. miles), with nearly 1,600km (1,000 miles) of shoreline. Underground rivers and natural wells, called cenotes, are a peculiar feature of this region.

Of course, the primary allure of the Yucatán peninsula for tourists is its long Caribbean coast, stretching the entire coast of the state of Quintana Roo. The swath of coast from Cancún south to Tulum has been dubbed the Riviera Maya; south from there to the Belize border is the Costa Maya. This coastline has an enormous array of wildlife, including hundreds of species of birds. The Gulf Coast beaches, while good enough, don't compare to those on the Caribbean. National parks near Celestún and Río Lagartos on the Gulf Coast are home to amazing flocks of flamingos.

Things change, however, when you move inland, into the states of Yucatán, the northern portion of the peninsula, and Campeche, the western portion. The landscape is dotted by crumbling haciendas and the stark ruins of ancient cities. This is the world of the present-day Maya, where life moves slowly in simple villages bordered by rock walls and small cornfields. And in the cities and towns, such as Mérida and Izamal in Yucatán state, and Campeche in Campeche state, you'll find the traditional Yucatán, with its highly pronounced regional flavor, and a way of life informed by centuries-old traditions.

To present the Maya world in its entirety, this guide also covers the states of Tabasco and Chiapas. The Gulf Coast state of Tabasco was once home to the Olmec, the mother culture of Mesoamerica. At Villahermosa's Parque-Museo La Venta, you can see the impressive 40-ton carved rock heads that the Olmec left behind.

San Cristóbal de las Casas, in Chiapas, inhabits cooler, greener mountains, and is more in the mold of a provincial colonial town. Approaching San Cristóbal from any direction, you see small plots of corn tended by colorfully clad Maya. The surrounding villages are home to many craftspeople, from woodcarvers to potters to weavers. In the eastern lowland jungles of Chiapas lie the classic Maya ruins of Palenque. Deeper into the interior, for those willing to make the trek, are the ruins of Yaxchilán and Bonampak.

Natural Life & Protected Areas -- The Yucatán state's nature preserves include the 47,200-hectare (116,600-acre) Ría Lagartos Biosphere Reserve north of Valladolid -- where you'll find North America's largest flock of nesting flamingos -- and the 5,600-plus-hectare (13,800-acre) Celestún Wildlife Refuge, which harbors most of the flamingos during nonnesting season. The state also has incorporated nature trails into the archaeological site of Dzibilchaltún, north of Mérida.

In 1989, Campeche state set aside 71,480 hectares (176,630 acres) in the Calakmul Biosphere Reserve that it shares with Guatemala. The area includes the ruins of Calakmul, as well as acres of thick jungle.

Quintana Roo's protected areas are some of the region's most wild and beautiful lands. In 1986, the state set aside the 520,000-hectare (1.3-million-acre) Sian Ka'an Biosphere Reserve, conserving a significant part of the coast in the face of development south of Tulum. Isla Contoy, also in Quintana Roo, off the coast of Isla Mujeres and Cancún, is a beautiful island refuge for hundreds of birds, turtles, plants, and other wildlife. Cozumel's Chankanaab National Park gives visitors an idea of the biological importance of Yucatán's lengthy shoreline: Four of Mexico's eight marine turtle species -- loggerhead, green, hawksbill, and leatherback -- nest on Quintana Roo's shores, and more than 600 species of birds, reptiles, and mammals have been counted.

Tabasco, though a small state, has set aside a vast preserve of wetlands called Pantanos de Centla, just northeast of Villahermosa. Three reserves in Chiapas encompass jungles and lakes, and some of Mexico's most bio-diverse lands. The largest by far is the nature preserve called Montes Azules, the old homeland of the Lacandón Indians in the extreme eastern lowlands bordering Guatemala. Not far from San Cristóbal de las Casas is also a small preserve of high cloud-forest habitat called Huitepec. A good distance west of Tuxtla Gutiérrez, the state capital, is an extensive nature preserve containing upland forests called Selva del Ocote.

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.