Chichen Itza rose on the dry limestone plain of the northern Yucatan, a region with no surface rivers. Its water came from cenotes, sinkholes that line up with fractures along the buried rim of the Chicxulub crater, where a freshwater lens floats over oxygen-starved saltwater that preserves wood, cloth, and rubber. In 2015 electrical resistivity tomography revealed a hidden cenote directly beneath the Temple of Kukulkan, El Castillo, placing the pyramid over a portal to Xibalba. Between 900 and 1050 AD the city filled the void left by the classic Maya collapse and declining rivals like Yaxuna and Coba, running a maritime trade network through ports like Isla Cerritos that brought obsidian from central Mexico and gold from southern Central America.

The city declined around 1100 AD but stayed sacred. In 1532 Francisco de Montejo the Younger tried to make it his capital, Ciudad Real, until a Maya siege forced him to flee in 1534. U.S. Consul Edward Herbert Thompson bought the Hacienda Chichen in 1894 and dredged the Sacred Cenote from 1904 to 1910, and Mexico’s Supreme Court cleared him in 1944. In 2025 the site drew 9.9 million visitors.

• A 2025 3D model of Castillo Sub, an earlier pyramid inside El Castillo that held a red jaguar throne inlaid with jade
• The equinox serpent shadow that appears for weeks, and a handclap echo on the stairs that mimics the quetzal bird
• The Great Ball Court, 168 by 70 meters, with carvings of a decapitated player whose blood turns into snakes
• Gamma ray spectrometry in 2025 showing some North Temple blocks decaying faster than local outcrops
• DNA from over 100 children in a nearby chultun, all boys aged three to six including identical twins, linked to the Hero Twins of the Popol Vuh