Underground Mayan Temples
The Maya believed in an Underworld, a mythical world of the dead, which they called Xibalba. Described in the sacred text known as the Popul Vuh, the soul's trip to Xibalba was anything but pleasant. Guided by mythical dog that could see in the dark, the traveling soul would have to pass rivers of scorpions, bat filled houses and lots of blood. Archaeologists have found several cave systems with a series of temples in Mexico, Guatemala, and Belize and they believe that they may have been constructed by Mayans as a way to reach Xibalba.
For example in 2008 archaeologists found eleven sacred temples in underground caverns in Mexico's Yucatan Peninsula. The caverns were connected by very narrow tunnels and the group of temples even included an underground road that was approximately 330 feet in length. Inside the caverns archeologists found stone carvings, but also ceramic offerings and even human remains. In Guatemala, new ground penetrating radar has revealed a network of underground tunnels under the Maya pyramid complex at Tikal. This complex system has been mapped and extends a dull 500 miles (800 km). Although these sites are somewhat different, they all used cavern systems that were located deep in jungle areas as a location for temple complexes.