El Castillo (Temple of Kukulcán), Chichén Itzá
How did the Maya of Chichén Itzá encode a 365-day solar calendar into a stone pyramid's stairways and platforms, and orient it so precisely that the setting sun paints a serpent of light down its staircase only at the equinoxes?
c. 800-1000 CE (Terminal Classic period), atop an older substructure from c. 600-800 CE · Chichén Itzá, Yucatán, MexicoAdded July 2026