The Temple of Kukulcán (El Castillo), Chichén Itzá
Photograph by M.O.G.G., 2006

Chichén Itzá, a UNESCO World Heritage Site located in the Yucatán Peninsula of Mexico, is one of the most significant archaeological complexes of the Maya civilisation, with its most iconic structure being the Temple of Kukulcán, also known as El Castillo. This step-pyramid, dedicated to the feathered serpent deity Kukulcán, exemplifies the Maya's advanced understanding of astronomy, mathematics, and engineering. The pyramid has four sides, each with 91 steps, which, when combined with the single platform at the top, total 365 steps—matching the number of days in a solar year. During the spring and autumn equinoxes, a remarkable play of light and shadow creates the illusion of a serpent slithering down the pyramid's steps, symbolising Kukulcán’s descent to Earth. Beneath the visible structure lies an older pyramid, and further excavations revealed a subterranean cenote (sinkhole), believed to have been a site for sacred rituals. Built during the Terminal Classic period (c. 800–1000), the Temple of Kukulcán reflects the fusion of Maya and Toltec influences, displaying intricate carvings, including depictions of warriors and serpents, which highlight the cultural and religious syncretism of the time.