The Temple of Kukulcán, also known as El Castillo, is a step pyramid located in the ancient city of Chichen Itza in Mexico. It was built by the Maya civilization around the 12th century and is dedicated to the feathered serpent deity, Kukulcán. The pyramid stands about 24 meters tall and features 91 steps on each of its four sides, totaling 365 steps, which correspond to the days of the year. The temple is renowned for its architectural precision and astronomical significance. During the spring and autumn equinoxes, the setting sun casts shadows that create the illusion of a serpent slithering down the pyramid's staircase. This phenomenon highlights the Maya's advanced understanding of astronomy and their connection to nature.