The Castillo - A stepped pyramid-temple, which records the equinoxes in a unique way. The sun creates a shadow of a huge 'snake' to ascend the steps in spring, and descend again in autumn (1). Whether or not this was a deliberate design feature is speculative, but other astronomical features at the site certainly lend weight to the idea that it was intentional. Each step corresponds to a day, each platform to a Mayan month. The temple is erected above the 365 steps. (17).

Chronology -  It is estimated that the Temple of the warriors was built around 1,100 AD.  (12)

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