Photo 3.  GPR profile of transect starting at 00N (NE corner of the Castillo Pyramid) and going east
about 30 meters.  The plaza fill is disrupted in the center of the image.  This indicates that the fill
and floors had been excavated in the form of a trench about 10 meters wide and 4 meters deep,
parallel to the pyramid, and extending from the east stairway north about 100 meters. The Maya
later refilled the trench.  Courtesy of William Sauck.