The site occupies 6.5 sq. km (2 1/2 sq. miles), requiring most of a day to see it all. The ruins are open daily from 8am to 5pm, service areas from 8am to 10pm. Admission for foreigners is 166 pesos, free for children 11 and younger. A video camera permit costs 45 pesos. Parking is extra. You can use your ticket to reenter on the same day. The sound-and-light show (worth seeing as you're being charged for it anyway), is held at 7pm fall and winter, or 8pm spring and summer. The narrative is in Spanish, but headsets are available for rent in several languages. The real reason for seeing the show is the lights, which show off the beautiful geometry of the city.

The large, modern visitor center at the main entrance consists of a museum, an auditorium, a restaurant, a bookstore, and bathrooms. Licensed guides who speak English or Spanish usually wait at the entrance and charge around 450 pesos for one to six people (there's nothing wrong with approaching a group of people who speak the same language and offering to share a guide). You can also see the site on your own, but the guides can point out architectural details you might miss on your own.

Chichén Itzá has two parts: the central (new) zone, which shows distinct Toltec influence, and the southern (old) zone, with mostly Puuc architecture. The most important structures are in New Chichén, but the older ones are also worth seeing.

El Castillo -- As you enter from the tourist center, the icon of Yucatán tourism, the magnificent 25m (82-ft.) El Castillo (also called the Pyramid of Kukulkán) is straight ahead across a large, open grassy area. It was built with the Maya calendar in mind. The four stairways leading up to the central platform each have 91 steps, which, added to the platform, totals the 365 days of the solar year. The 18 terraces flanking the stairways on each face of the pyramid add up to the number of months in the Maya religious calendar. The terraces contain a total of 52 panels, representing the 52-year cycle when the solar and religious calendars reconverge. The pyramid, now closed to climbers, is aligned so that the spring or fall equinox (Mar 21 or Sept 21), triggers an optical illusion: The setting sun casts the terraces' shadow onto the northern stairway, forming a diamond pattern suggestive of a snake's geometric designs. As it meets the giant serpent's head at the bottom, the shadow appears to slither down the pyramid as the sun sets, a phenomenon that brings hordes of visitors every year. (The effect is more conceptual than visual, and frankly, the ruins are much more enjoyable on other days when they are less crowded.)

Like most Maya pyramids, El Castillo was built over an earlier structure. A narrow stairway at the western edge of the north staircase leads inside to a sacrificial altar-throne -- a red jaguar encrusted with jade. The stairway is open from 11am to 3pm and is cramped, usually crowded, humid, and uncomfortable. A visit early in the day is best. Photos of the jaguar figure are not allowed.

Juego de Pelota (Main Ball Court) -- Northwest of El Castillo is Chichén's main ball court, the largest and best preserved anywhere, and only one of nine ball courts built in this city. Carved on both walls are scenes showing Maya figures dressed as ball players and decked out in heavy protective padding. A headless player kneels with blood shooting from his neck; another player holding the head looks on.

Players on two teams tried to knock a hard rubber ball through one of the two stone rings placed high on either wall, using only their elbows, knees, and hips. According to legend, losers paid for defeat with their lives. However, some experts say the victors were the only appropriate sacrifices for the gods. Either way, the game, called pok-ta-pok, must have been riveting, heightened by the ball court's wonderful acoustics.

The North Temple -- Temples stand at both ends of the ball court. The North Temple has sculptured pillars and more sculptures inside, as well as badly ruined murals. The acoustics of the ball court are so good that from the North Temple, a person speaking can be heard clearly at the opposite end, about 135m (443 ft.) away.

Temple of Jaguars -- Near the southeastern corner of the main ball court is a small temple with serpent columns and carved panels showing warriors and jaguars. Up the steps and inside the temple, a mural chronicles a battle in a Maya village.

Tzompantli (Temple of the Skulls) -- To the right of the ball court, the Temple of the Skulls obviously borrows from the post-Classic cities of central Mexico. Notice the rows of skulls carved into the stone platform; when a sacrificial victim's head was cut off, it was impaled on a pole and displayed with others in a tidy row. Also carved into the stone are pictures of eagles tearing hearts from human victims. The word "Tzompantli" is not Mayan, but comes from central Mexico.

Platform of the Eagles -- Next to the Tzompantli, this small platform has reliefs showing eagles and jaguars clutching human hearts in their talons and claws, as well as a human head emerging from the mouth of a serpent.

Platform of Venus -- East of the Tzompantli and north of El Castillo, near the road to the Sacred Cenote, is the Platform of Venus. In Maya and Toltec lore, a feathered monster or a feathered serpent with a human head in its mouth represented Venus. This is also called the tomb of Chaac-Mool, for the figure that was discovered "buried" within the structure.

Sacred Cenote -- Follow the dirt road (actually an ancient sacbé, or causeway) leading north from the Platform of Venus for 5 minutes to get to the great natural well that may have given Chichén Itzá (the Well of the Itzáes) its name. This well was used for ceremonial purposes, and the bones of both children and adult sacrificial victims were found at the bottom.

Edward Thompson, who was the American consul in Mérida and a Harvard professor, purchased the ruins of Chichén early in the 20th century and explored the cenote with dredges and divers. He uncovered a fortune in gold and jade, most of which ended up in Harvard's Peabody Museum of Archaeology and Ethnology -- a matter that disconcerts Mexican classicists to this day. Excavations in the 1960s yielded more treasure, and studies of the recovered objects show that the offerings came from throughout the Yucatán and even farther away.

Templo de los Guerreros (Temple of the Warriors) -- The Toltec influence is especially evident on the eastern edge of the plaza. Due east of El Castillo is one of Chichén Itzá's most impressive structures, the Temple of the Warriors, named for the carvings of warriors marching along its walls. The temple and the rows of almost Greco-Roman columns flanking it are also called the Group of the Thousand Columns, and it recalls the great Toltec site of Tula. A figure of Chaac-Mool sits at the top of the temple (visible only from a distance now that the temple is closed to climbers), surrounded by columns carved in relief to look like enormous feathered serpents. South of the temple was a square building that archaeologists call El Mercado (The Market); a colonnade surrounds its central court.

The main Mérida-Cancún highway once ran straight through the ruins of Chichén, and though it has been diverted, you can still see the great swath it cut. South and west of the old highway's path are more impressive ruined buildings.

Tumba del Gran Sacerdote (Tomb of the High Priest) -- Past the refreshment stand to the right of the path, the Tomb of the High Priest shows both Toltec and Puuc influence. The 9m (30-ft.) pyramid, with stairways on each side depicting feathered serpents, bears a distinct resemblance to El Castillo. Beneath its foundation is an ossuary (a communal graveyard) in a natural limestone cave, where skeletons and offerings have been found.

Casa de los Metates (Temple of the Grinding Stones) -- This building, the next one on your right, is named after the Maya's concave corn-grinding stones.

Templo del Venado (Temple of the Deer) -- Past Casa de los Metates is this fairly tall, though ruined, building. The relief of a stag that gave the temple its name is long gone.

Chichanchob (Little Holes) -- This temple has a roof comb with little holes, three masks of the rain god Chaac, three rooms, and a good view of surrounding structures. It's one of Chichén's oldest buildings, built in the Puuc style during the late Classic period.

El Caracol (The Observatory) -- One of Chichén Itzá's most intriguing structures is in the old part of the city. From a distance, the rounded tower of El Caracol ("The Snail," for its shape), sometimes called The Observatory, looks like any modern observatory. Construction of this complex building with its circular tower was carried out over centuries, acquiring additions and modifications as the Maya's careful celestial observations required increasingly exact measurements. Quite unlike other Maya buildings, the entrances, staircases, and angles are not aligned with one another. The tower's circular chamber has a spiral staircase leading to the upper level. The slits in the roof are aligned with the sun's equinoxes. Astronomers observed the cardinal directions and the approach of the all-important spring and autumn equinoxes, as well as the summer solstice.

On the east side of El Caracol, a path leads north into the bush to the Cenote Xtoloc, a natural limestone well that provided the city's daily water supply. If you see lizards sunning there, they may well be xtoloc, the species for which this cenote is named.

Templo de los Tableros (Temple of the Panels) -- Just south of El Caracol are the ruins of a temazcalli (a steam bath) and the Temple of Panels, named for the carved panels on top. A few traces remain of the much larger structure that once covered the temple.

Edificio de las Monjas (Edifice of the Nuns) -- This enormous nunnery is reminiscent of the palaces at sites along the Puuc route. The new edifice was built in the late Classic period over an older one. To prove this, an early 20th-century archaeologist put dynamite between the two and blew away part of the exterior, revealing the older structures within. Indelicate, perhaps, but effective.

On the east side of the Edifice of the Nuns is Anexo Este (annex), constructed in highly ornate Chenes style with Chaac masks and serpents.

La Iglesia (The Church) -- Next to the annex is another of Chichén's oldest buildings, the Church. Masks of Chaac decorate two upper stories; a close look reveals armadillo, crab, snail, and tortoise symbols among the crowd of Chaacs. These represent the Maya gods, called bacah, whose job it was to hold up the sky.

Akab Dzib (Temple of Obscure Writing) -- Beloved of travel writers, this temple lies east of the Edifice of the Nuns. Above a door in one of the rooms are some Mayan glyphs, which gave the temple its name because the writings are hard to make out. In other rooms, traces of red handprints are still visible. Reconstructed and expanded over the centuries, Akab Dzib might be the oldest building on the site.

Chichén Viejo (Old Chichén) -- For a look at more of Chichén's oldest buildings, constructed well before the time of Toltec influence, follow signs from the Edifice of the Nuns southwest into the bush to Old Chichén, about 1km (2/3 mile) away. Be prepared for this trek with long trousers, insect repellent, and a local guide. Attractions here include the Templo de los Inscripciones Iniciales (Temple of the First Inscriptions), with the oldest inscriptions discovered at Chichén, and the restored Templo de los Dinteles (Temple of the Lintels), a fine Puuc building. Some of these buildings are being restored.

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.