Vernal equinox at Chichen Itza

Today is the vernal equinox, the beginning of spring in the northern hemisphere, when night and day are of almost equal length all over the world. People flock to ancient monument Chichen Itza in Yucatan, Mexico where the shadow play produced by the sun hitting the pyramid create the illusion of a serpent going down the side of the stone staircase.

People from all over the world witness the spring equinox with its famous shadowplay at the Mayan Kukulkan pyramid at Chichen Itza.
(Jannis Werner/age fotostock/Robert Harding)

Visitors climb the steep steps of a ruin in Chichen Itza.
(Kirk Mastin/Robert Harding)

The Mayan Kukulkan pyramid with the snake illusion at the vernal equinox.
(age fotostock/Robert Harding)

Jaguar platform, with the pyramid in the background.
(age fotostock/Robert Harding)

Quetzalcoatl serpent-god, Temple of the Warriors at Chichen-Itza.
(Robert Frerck/Robert Harding)

Pyramid of Kukulcan seen through two pillars, Chichen Itza.
(age fotostock/Robert Harding)

Detail of the Mayan ruins, Chichen Itza.
(Gavin Hellier/Robert Harding)

See more photos of Chichen Itza here