If you want to learn more about the ancient Mayas, where do you go? You can seek out ruins still cloaked in lush tropical forests and accessible only through back jungle trails or find some close to airports or beach resorts that are merely a bus ride away.

Pyramids, temples, palaces, observatories and ball courts are common to many of the hundreds of classic Mayan sites throughout Mexico and Central America.

Mayan archaeologists and enthusiasts suggest these ruins as among the most important or accessible:

Chichen Itza: A day trip from Cancun, this ancient city is the most visited ruins in the Yucatan Peninsula, with an average of 5,000 visitors a day. The six-square-mile site includes a mix of Mayan and Toltec architectural styles. The focal point, the 79-foot-tall pyramid of Kululk, takes on a mystical look twice a year: At the spring and autumn equinoxes, the sun's shadow creates the illusion of a snake moving down the pyramid.

The tourist floodgates were opened when UNESCO declared Chichen Itza a World Heritage site in 1988, and its structures are threatened by the wear and tear of foot traffic and vandalism.

Uxmal: Pronounced "Oosh-mahl," this well-built, compact site in western Yucatan (about an hour drive from Merida) is in better condition than many other ruins. In his writings, 19th-century explorer John Lloyd Stephens recounted stories of the human sacrifice at the site's tallest temple, the House of the Magician: With the victim still alive, the priest would rip out the heart with a flint knife and throw the body (allegedly still moving) down the steep steps.

Palenque: "If you want to get a sense of the absolute beauty and grandeur of the height of the Maya, Palenque is one of the most beautiful cities of the world," said Elin Danien, research associate at the University of Pennsylvania Museum of Archaeology and Anthropology.

Although this site in the foothills of the Chiapas mountains is smaller than Chichen Itza, it boasts some of the grandest buildings, as well as best-preserved bas reliefs.

Tikal: See story on this page.

Copan: In western Honduras, this site has some of the best-preserved carved stone slabs (stelae) and sculpted decorations. Among the highlights is a hieroglyphic stairway. The Mayas often built one temple over another, and excavation through a tunnel by Penn archaeologists has allowed examination of several layers.