The temple of Kukulkan, also known as El Castillo is situated in modern day Mexico. The temple is dedicated to a Mayan god Kukulkan, a Feathered Serpent deity. During the spring and autumn equinoxes, the weak sun strikes the northeast corner of the pyramid and cast a series of triangular shadows to northwest pillar, creating the illusion of a feathered serpent crawling down the edges of the pyramid. I would be a spine-tilting experience.