The city takes part of its name from the large wells that were its only permanent source of water. Spanish records report that live victims were thrown into the sacred well as a sacrifice to the rain god Chaac, who lived in its depth. The Maya also built this circular building believed to be an observatory. By carefully watching the stars, the Maya developed a 365-day calendar and could even predict solar eclipses.

Chichen Itza was also influenced by other cultures. Around the year 1,000, experts believe this famous Mayan city was invaded by foreigners, among them, possibly the Toltec of central Mexico and the Itza people. It was the Itza who built the city's most famous building, a pyramid the Spanish called "El Castillo," or the castle. This 79-foot pyramid has a total of 365 steps, the same number as the days in a solar year.

And it guards another secret, testament to the Maya's skill at math and astronomy. Twice a year, on the day of the spring and autumn equinoxes, a shadow falls on El Castillo in the shape of a serpent. As the sun sets, the snake appears to wriggle down the steps of the pyramid until it finally joins the serpent's head at the base of the staircase.

Chichen Itza's Ball Court is the largest known ancient ball court in the Americas. Here, players would strive to hit a 12-pound rubber ball through the scoring rings set high on the parallel walls. At the end of this deadly serious game, the losers would be sacrificed.

A bustling trading center past the year 1,000, Chichen Itza endured long after other Mayan cities have been abandoned. But eventually, it likely fell victim to the same forces that felled other Mayan cities, a combination of prolonged droughts, exhausted soils and a top-heavy class of royals, whose costly wars and lavish rituals overtaxed the Maya people.

Sometime in the 1,400s, the people of Chichen Itza abandoned their city to the jungle. But today, its imposing ruins still stand amid the rainforest, an impressive and enduring monument to the proud Maya civilization that built it.