The Ossuary at Chichén Itzá, also referred to as the High Priest's Grave, is named so for its communal burial chamber located underneath the pyramid's foundation. The pyramid is roughly 30 feet high with four stairways on each side, with a sanctuary in the center and a gallery with a portico in the front. The sides of the stairways are decorated with interlaced feathered serpents. Pillars associated with this building are in the form of the Toltec feathered serpent and human figures. Between the first two pillars is a square stone-lined vertical shaft in the floor which extends downwards to the base of the pyramid, where it opens up on a natural cavern. The cave is 36 feet deep and when it was excavated, bones from several human burials were identified along with grave goods and offerings of jade, shell, rock crystal and copper bells.