There are no surface rivers to speak of in Yucatan. All the rainwater filters through the porous limestone and flows underground.
Over the years this constant erosion created vast systems of caves with wonderful decorations of stalactites and stalagmites, from fields of young soda straws to solitary old columns. Then as the water level rose, these caves were flooded. Cenotes are openings to these forgotten worlds, usually in places where the cave's roof collapsed.
Located between Tulum and Coba are five of these cenotes.
