As the sun sets in the west and the shadows lengthen in the ancient Mayan city of Chichen Itza, a collective sigh of amazement goes up from thousands of people standing at the foot of the Pyramid of Kukulcan on March 20-21, the spring equinox. They gather to witness an amazing spectacle, the mysterious shadow of a serpent rippling across the stone, the powerful symbol of an ancient god returning to earth.

Dominating the Great Plaza, the 25-meter-high El Castillo or Pyramid of Kukulcan is a feat of ancient engineering and a solar clock, aligned so precisely by its creators to catch the rays of the setting sun on the days of the spring and fall equinoxes in March and September. Isosceles triangles of light and shadow form along the side of the north staircase and the figure of a snake appears, merging with the head of a stone serpent at the foot of the building. The illusion is created of a gigantic snake slithering down from the heavens and across the ground towards the Sacred Cenote.

The snake symbolizes Kukulcan, a great leader and ruler of Chichen Itza associated with the feathered serpent god (known as Quetzalcoatl in central Mexico), who is said to return to earth to give hope to his followers. It also heralds the spring planting and fall harvest seasons for the Maya.

In ancient times, the city’s rulers, priests and astronomers would scan the heavens for portents, recording the movements of the stars and charting the passage of the seasons. They could predict the Equinoxes and on this day, they would have summoned their subjects to the main square for a ceremony invoking Kukulcan with prayers, rites and offerings. Imagine the awe of the populace as the shadow of the serpent appeared before them.

Experts believe that Kukulcan, the leader who gave his name to the pyramid, may have come from the west and that he resided at Chichen Itza some time in the 10th century. This coincided with the period when the city was ruled by the Itzae, a group of seafaring warrior traders or Putun from Chontal Maya territory in Tabasco and Campeche who had political and commercial ties with central Mexican cultures.

Built some time between A.D. 650 and 800 using only stone tools and with later modifications, possibly from 1000 to 1150, the pyramid is also a symbol of the Mayan calendar. Sitting on a square base measuring 55.5 meters on all sides, the pyramid has nine terraces, divided by two stairways. The number of terraces and wall panels coincides with the number of months in the ancient year (18) and years in a calendar round (52), respectively, and the number of steps in the staircases (91), in addition to the top platform, the entrance to the temple, equals 365, the days in the year.

This year, the Spring Equinox falls on March 20 but it is traditionally observed on March 21 at Chichen Itza as it coincides with an official Mexican holiday, the birthday of Benito Juarez, a 19th-century reformist president and national hero. The light and shadow snake is visible the day before and after the equinox, cloud cover permitting.

The Pyramid of Kukulcan is just one of the marvels awaiting discovery at Chichen Itza. This huge Mayan metropolis is a UNESCO World Heritage Site and was voted one of the New Seven Wonders of the World in a global online poll in 2007.

Dawn at Dzibilchaltun on the Equinox

Chichen Itza is not the only Mayan ceremonial center in the Yucatán to have temples with solar, lunar or planetary alignments. The doorway of the Temple of The Seven Dolls at Dzibilchaltun (13 miles north of Mérida) makes a perfect frame for the rising sun on the day of the Equinox.

Chichen Itza and Valladolid

If you would prefer to explore Chichen Itza at your own pace, why not arrange a private guided tour or rent a car and stop off in the colonial city of Valladolid on the way? This peaceful pueblo magico is steeped in history and tradition and is the perfect spot to spend a few hours before making your way to Chichen Itza.

Start with the spectacular Zaci Cenote and then stroll through the main square to the Cathedral. On Calle 40, just a short walk from the main square is Casa de Los Venados, a 17th-century restored mansion that is a private home and a museum with an impressive collection of more than 3,000 pieces of Mexican folk art. Guided tours of the property are available at 10 a.m. and are recommended. Admission is a $60 peso donation for local charities.

Then walk along Calzada de Los Frailes, the street leading to San Bernardino Church and Sisal Convent. You’ll pass more restored mansions, craft shops, a workshop where cacao is transformed into chocolate using traditional techniques, and the Coqui Coqui perfumery where native flowers and fruits are transformed into soaps, candles, essences and fragrances.

To the north of Valladolid, a side trip to the Mayapan artisanal distillery gives you a glimpse of the world of the blue agave, the plant that gives us tequila. Native to the state of Jalisco, the plant has adapted to the climate and soils of the Yucatan and is thriving in the fields surrounding the distillery.

When the plants are seven years old they are harvested for their root stem or piña, which is then roasted. The sugary liquid crushed from the cooked piña is fermented, distilled and stored in wooden barrels until ready to be bottled as blanco, reposado or añejado varieties of Mayapan.

Mayapan is not the only spirit produced in Valladolid, the town is also famous for Xtabentun, the fragrant anise-flavored liqueur of the Yucatan, which is made from honey and a native flower.

More impressive cenotes await you en route to Chichen Itza; Dzitnup and Samula are in villages on the outskirts of Valladolid (via Highway 180) and Balancanche Caves and Ik-Kil Cenote are located a short drive from the archaeological site.

Planning your Chichen Itza Trip

Thomas More Travel www.thomasmoretravel.com offers a variety of trips to Chichen Itza and you can also arrange a private tour to take you to the places mentioned in this post. An alternative is to rent a car and explore on your own.

The new evening Light & Sound Show in Chichen Itza is highly recommended if you decide to enjoy cocktails and an early dinner at one of the nearby hotels and then return to the site for the multimedia event.

Chichen Itza is located in the eastern Yucatan, 200 kilometers/125 miles from Cancun via the toll road (take the exit at Piste). An alternative route that takes longer is Highway 180 via Valladolid.