This step-pyramid temple dominates the platform, on a small scale.
Like its larger neighbor, El Castillo, it has four sides with staircases on each side. There is a temple on top, but different from El Castillo, at the center is an opening into the pyramid which leads to a natural cave 12 m. below.
Edward H. Thompson excavated this cave in the late 1800s, and because he found artifacts such as jade beads and several skeletons, he named the structure The High Priests' Temple.
But archaeologists today do not believe that the structure was either a tomb or that the personages buried in it were priests.