Calakmul is a huge and impressive Maya site south of Xpujil, a small town halfway the Yucatan Peninsula. One of my favorites to visit, because its not well know yet, hence not crowded with tourists, and ofter yo uwill find yourself alone there, wandering through the jungle, listening to the howler monkeys.
This archeological site you cannot visit while staying at Maya Luna, only to reach Xpujil will alone take you some 2.5 hours. After that its still 40 km south to reach Calakmul. But we recomend it absolutely if you are on a tour and have the time to go south. Stay with Rick and Diane, in their small hotel Rio Bec Dreams. They organize tours to Calakmul and other archeolical sites in the neighbourhoud (which are a lot) and are both very knowledgable about the Maya culture and history. Very good food also at their Restaurant.