The entire front wall and mansard roof of the Temple of the Foliated Cross have fallen, which gives the building its unusual appearance. It originally looked much like the Temple of the Sun, with three entrance doorways and four stuccoed piers. However, it's current condition allows us to see the construction of its interior spaces. Mary Ellen Miller writes:
"East of the aqueduct, the three temples of the Group of the Cross (the Temples of the Sun, the Cross and the Foliated Cross) show yet another architectural innovation. In this design -- common to each of the temples -- the two parallel galleries are intersected at right angles by another corbeled passage, creating a great chamber.
Each temple also has an inner shrine at the rear of the building. The post and lintel doorway, as well as the usual mansard roof, conceal the interior space. At Palenque the achievement of private, interior space is as significant as the negative, public space defined by the volumes of the buildings."
Mary Ellen Miller, The Art of Mesoamerica from Olmec to Aztec, p. 130