Kukulkan's pyramid.

Chichen-Itza (chee-chehn eet-sah) in Maya, was a sacred city of the Itza and the name literally means: "Mouth of the well of the Itza". Located 75 miles east of Mérida, the capital of the State of Yucatan, Mexico; this archaeological site is rated among the most important of the Maya culture and covers an area of approximately six square miles where hundreds of buildings once stood. Now most are mounds but more than thirty may still be seen by tourists.

Possibly the best known construction in Chichen itza is Kukulkan's Pyramid. El Castillo (Kukulkan-Quetzalcoatl), a square-based, stepped pyramid that is approximately 75 feet tall. This pyramid was built for astronomical purposes and during the vernal equinox (March 20) and the autumnal equinox (September 21) at about 3pm the sunlight bathes the western balustrade of the pyramid's main stairway. This causes seven isosceles triangles to form imitating the body of a serpent 37 yards long that creeps downwards until it joins the huge serpent's head carved in stone at the bottom of the stairway. Mexican researcher Luis El Arochi calls it "the symbolic descent of Kukulkan" (the feathered serpent), and believes it could have been connected with agricultural rituals. Its magnificent architecture has elements of the Maya-Tolteca combination and some buildings on Puuc style of the classic period. The Kukulkan pyramid, also known as the castle, where every year, during the spring equinox, anyone can enjoy the light and dark effect, produced by its astronomical orientation, projecting the shape of an snake descending by the stairs.