According to the Popol Vuh, an ancient Maya scripture, the route was full of obstacles, including rivers filled with scorpions and houses shrouded in darkness or swarming with shrieking bats, said Guillermo de Anda, one of the lead investigators at the site. The souls of the dead were said to have followed a mythical dog who could see at night.
Mexican archaeologists have discovered a maze of stone temples in underground caves, some submerged in water and containing human bones, which ancient Mayans believed was a portal where dead souls entered the underworld. Clad in scuba gear and edging through narrow tunnels, researchers discovered the stone ruins of eleven 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.