#00414 / Nature
Longest Explored Underwater Cave System
Evidence-backed541.791km
Sistema Ox Bel Ha
Tulum Municipality, Quintana Roo, Yucatan Peninsula, Mexico · Sistema Ox Bel Ha
Sistema Ox Bel Ha in Quintana Roo, Mexico, ranks among the world's longest mapped underwater cave systems. CINDAQ's 2025 annual report lists 541.791 km of confirmed surveyed passages, a figure that may grow as exploration continues.
