This photo actually contains all three temples in the Cross Group. The Temple of the Cross is to the left, the Temple of the Foliated Cross is the smaller temple in the center of the photo, and the Temple of the Sun appears partially obscured behind the foreground trees to the far right (the small temple directly to the left of the Temple of the Sun is Temple XIV).
"The low relief carved stone tablets in the sanctuaries of the Cross Group temples, the Temple of the Cross, the Temple of the Sun, and the Temple of the Foliated Cross, built by Chan Bahlum when he was forty-nine years old, are unique as to size and the complicated hieroglyphic information concerning the purpose of each temple, as well as the role of the three Palenque Tirad Gods GI, GII, and GIII, and the dynastic history of the kings and their legitimate right to rulership.
Unlike any other group of buildings in the entire Maya realm, these three temples play the role of a Maya codex (bark paper book) in three parts. History, both real and mythical, is recorded, and it unfolds like the pages of a book from temple to temple."
Merle Greene Robertson, Sculpture and Murals of the Usumacinta Region, in MAYA [Palazzo Grassi, Venice 1999] p.302-3.