Temple of Kulkulkan is the centerpiece of the Mayan culture at
Chichén Itza, Mexico. Kukulkan is the Maya name for Quetzalcoatl
but the temple is also referred to as "El Castillo"
step pyramid has a ground plan of square terraces with stairways
up each of the four sides to the temple on top. On the Spring
and Autumn equinox, at the rising and setting of the sun, the
corner of the structure casts a shadow in the shape of a plumed
serpent - Kukulcan, or Quetzalcoatl - along the west side of the
north staircase. On these two annual occasions, the shadows from
the corner tiers slither down the northern side of the pyramid
with the sun's movement to the serpent's head at the base.