One of the most important structures in Palenque is the Tomb of Pakal, discovered in 1952 by Alberto Ruz Lhuillier inside the Temple of the Inscriptions. Pakal died on August 31, 683 at eighty years of age. He had assumed the throne on July 29, 615A.D. at the age of twelve, and ruled for 68 years. During his long reign—near the end of the Classic Period (AD 250-900)—Pakal transformed Palenque into a great city. Around AD 675, as an old man nearing death, he undertook the construction of his burial temple.
As the crypt is larger than the entrance to the chamber, it is thought that it was built before the pyramid. Pakal's body was placed in the limestone, body-shaped sarcophagus and then it was sealed with a 3.8 by 2.2 meter stone cover. Once the burial rites were completed and the chamber sealed with a layer of stucco, five or six sacrificial victims were laid in the small antechamber. The stairway inside the temple was filled with rubble, jade, pottery and shell offerings. A stone airshaft, called a "psychoduct," was built starting at a notch in the funeral chamber door and rising to the upper floor of the temple. According the late Linda Schele, a renowned researcher, the Maya believed that the shaft allowed a mythological serpent to rise from Pakal's tomb to the place occupied by his descendants.