Kukulkan is the Feathered Serpent of the Yucatec Maya, called Gucumatz by the Kiche Maya of the highlands and cognate with the Aztec Quetzalcoatl of central Mexico, a god of wind, rain and the arts of settled, civilised life. The feathered or plumed serpent, joining the bird of the sky and the snake of the earth, is one of the most ancient and widespread of all Mesoamerican deities, and among the Maya of the Yucatan he takes the form of Kukulkan. He is associated with the wind that brings the rains, with water and fertility, and with the knowledge and institutions of civilisation, writing, the calendar, and rulership, and he was among the most important gods of the Postclassic Maya cities of the peninsula.
Kukulkan's most famous surviving monument is El Castillo, the great stepped pyramid at Chichen Itza also known as the Temple of Kukulkan, engineered so that at the spring and autumn equinoxes the setting sun casts a shifting series of triangular shadows down the northern staircase's balustrade, creating the visual illusion of a giant serpent, its carved stone head already fixed at the base, slithering down the pyramid as the light changes; the effect draws large modern crowds each equinox and is generally accepted by archaeologists as an intentional feature of the building's design, one of the clearest surviving examples anywhere in the ancient world of architecture engineered to enact a god's myth through astronomy.