or the Pyramid of Kukulkán
Chichén Itzá (Yucatán), Mexico
Other than serving as a temple to the above mentioned god, this pyramide is, in fact, the Maya calender made stone: each starircase has 91 steps, which added to the single step at the main entrance amounts to 365. Other numbers relevant to the Maya calender recur throughout the construction (between the 9th and 12th centuries AD). Most remarkably, at sunset on the spring and autumn equinoxes, the great serpents' heads at the foot of the main staircase are joined to their tales (at the top) by an undulating body of shadow - an event of just a few hours that draws spectators, and awed worshippers, by the thousand.