A minor feature at Chichén Itzá, located maybe twenty feet from the southwest corner of the Observatory complex. Not included in the tour. My best guess? More practical than fantastical, I’m afraid: I think it was a well, a convenience for the astronomer-priests, too busy figuring out how many times Venus would be occluded by the moon in the next fifty-two years to consider a break for a beverage. No surprise the well filled up with debris in eight hundred years, and no surprise, what with all the other wonders just lying around in the jungle still uncovered, that something so mundane remains unexcavated.