Etched into this jade tablet is one of the earliest known depictions of the Mesoamerican cosmos. A pyramid-shaped mountain sits atop the open maw of a cave, an entrance to the primordial waters of the underworld. This mountain-cave motif embodies the three levels of the cosmos: the celestial mountaintop where the gods reside, the earth, and the watery underworld. Among the Nahua, this ancient concept is analogous to the altepetl (water-mountain), a symbol of both a land and its people. A maize plant directly above the mountain-cave represents the axis mundi, with four kernels marking the corners of the cosmos.