Exploring Mexico's Underworld - Guillermo de Anda

To keep secret the religious practice of human sacrifice, the Mayans held ceremonies in hard to reach underwater caves and cenotes, which are sinkholes. National Geographic Emerging Explorer Guillermo de Anda and his team are exploring the dark depths of the ocean surrounding the Yucatan Peninsula to find out more about this ancient Mayan ritual. Guillermo’s experiences cave diving show that not all archaeology involves sifting through dust and can actually be quite risky.