There's a legend that claims there's an entrance to the underworld in Mexico. Now experts think they found it. Hear about it at Urban Legends and Stranger truths. Hundreds of years ago, Francesco de Borgo, a Dominican priest, shared the story of a group of Spanish missionaries who explored the ruins of an ancient church in AXA, Mexico. Borgoa claimed the missionaries had discovered an underground temple with a vast system of tunnels and four interconnected chambers