Divers discover world's longest underwater cave system in Mexico (CNN) — Underwater archeologists in Mexico have discovered the world's largest flooded cave. The Great Maya Aquifer Project (GAM) team -- committed to studying the mysterious waters of Mexico's Yucatan peninsula -- spent years exploring the caves of Sac Actun and Dos Ojos in Tulum before connecting the two caverns together. The explorers' discovery marks the identification [...]