Kukulcán, Mayan pyramid in Mexico.
El Castillo, also known as the Temple of Kukulcan, is a Mesoamerican step-pyramid that dominates the center of the Chichen Itza archaeological site in the Mexican state of Yucatán.
Built by the pre-Columbian Maya civilization sometime between the 9th and 12th centuries CE, El Castillo served as a temple to the god Kukulkan.
The pyramid consists of a series of square terraces with stairways up each of the four sides to the temple on top, sculptures of plumed serpents run down the sides of the northern balustrade.
During the spring and autumn equinoxes, the late afternoon sun strikes off the northwest corner of the pyramid and casts a series of triangular shadows against the northwest balustrade, creating the illusion of a feathered serpent 'crawling' down the pyramid.
Each of the pyramid's four sides has 91 steps which, when added together and including the temple platform on top as the final 'step', produces a total of 365 steps (which is equal to the number of days of the Haab' year).
Location: Chichen Itza
Height: 200 m
Width: 55.5 m
Source: Wikimedia