The Central Plaza is the main attraction at Calakmul. It includes the main pyramids of Temple I and Temple II and the other larger temples at the site: Temple IV and Temple VII. Many stelae were standing in front of these temples; unfortunately, almost all of them were eroded so badly that I could not make out the carving or inscriptions. Temple I and Temple II are the highest points in Calakmul, so of course I loved walking up them.
Just a little side-note: you walk about a mile from the entrance to get to the Central Plaza.