There doesn't seem to be much information about this Mayan temple that stands at one end of the Great Ball Court. There are no indications that it was dedicated to any specific deity it seems. It name is derived from a bas-relief on the inside of one of the columns depicting a warrior with a long beard. Apparently depictions of bearded individuals on ancient Mayan structures are otherwise very rare. Perhaps this was simply a platform where Mayan nobles could watch the games. One interesting thing about the acoustics of the ball court is that a person speaking in a normal voice from here can be heard 100m away at the far end, and a single clap echoes like mad bouncing back and forth off the side walls .All the guides I noticed taking people around seemed to delight in demonstrating this. Click the image in the comments below for info on the ball court itself.