Archeologists have found a huge and complex water system underneath the tomb of the Mayan king Pakal, which lies at the bottom of the most important temple in the city of Palenque.

Arnoldo González de la Cruz, the head of the excavation, told a press conference that the underground canals provide a much more rounded hypothesis than previously available to explain why tomb and temple were built on that particularly site.

"The evidence supports the idea that this temple was built because of the existence of the spring," he said, adding that water-based hieroglyphs also support this idea. "They may have reproduced in a symbolic way the sinuous route the king hoped to take to the waters of the Mayan underworld."

Palenque, in the southern Mexican state of Chiapas, was the capital of the Mayan region of B'akaal, which means bone region. It was one of the biggest and most important Mayan city states between the fifth and ninth centuries AD. Pakal's military campaigns during his long rule in the seventh century consolidated the city's domination of the region. His sarcophagus was found beneath the Temple of the Inscriptions in 1952.

Water was at the center of many Mayan beliefs. The underworld, or Xibalbá, was inspired by the thousands of interconnected underground waterways that criss cross areas of Mayan presence in southern Mexico and Central America. They are accessible through cenotes, which are places where the surface rock has collapsed.

Underwater archaeology projects have discovered thousands of artefacts made of jade and gold, as well as stone figurines and human bones, suggesting rituals related with death.

González said the canals under the Temple of the Inscriptions in Palenque were originally discovered by accident in 2012, because of exploration wells dug around Pakal's tomb for conservation purposes.