Chichen Itza Equinox in Chichen Itza
Twice a year, on the spring and autumn equinoxes, the setting sun casts a shadow along the northern staircase of the Temple of Kukulkan at Chichen Itza that appears to connect with a carved serpent head at its base, creating the illusion of a giant snake descending the pyramid. The spring event, occurring around March 19 to 23, draws thousands of visitors to the Yucatan archaeological site each year to witness the multi-day phenomenon.
Sometime around the 9th or 10th century, Maya builders at Chichen Itza raised a pyramid dedicated to Kukulkan, the feathered serpent deity, and encoded a piece of astronomical theater directly into its stonework.