Mexican archaeologists have discovered a maze of stone temples in underground caves, some submerged and containing human bones, which ancient Mayans believed was a portal where dead souls entered the underworld.

Researchers discovered the stone ruins of 11 sacred temples and what could be the remains of human sacrifices at the site in the Yucatan Peninsula.

Archaeologists say Mayans believed the underground complex of water-filled caves leading into dry chambers - including an underground road stretching some 330 feet - was the path to a mythical underworld, known as Xibalba.

According to an ancient Mayan scripture the route was filled with obstacles, including rivers filled with scorpions, blood and pus and houses shrouded in darkness or swarming with shrieking bats.

The souls of the dead followed a mythical dog who could see at night.

Excavations over the past five months in the Yucatan caves revealed stone carvings and pottery left for the dead.

One of the lead investigators at the site Guillermo de Anda said: "They believed that life began here and at the moment of death they would go to the other side to Xibalba.

"The caves and pools served a practical purpose as they were useful for gathering water for daily life, but they also had an important spiritual component, which was they served as the entrance to the Mayan underworld."

In the Yucatan site investigators have found one 1,900-year-old ceramic vase, but most of the artefacts date back to between AD700 and AD850.

The Mayans built soaring pyramids and elaborate palaces in Central America and southern Mexico before mysteriously abandoning their cities around AD900.

© Independent Television News Limited 2009. All rights reserved.