World's longest underwater cave discovered in Mexico 

The world's biggest underwater cave has been discovered by divers in Mexico.The group connected two underwater caverns to reveal what is thought to be the biggest flooded cave on the planet.And it is believed that the discovery could help shed light on the ancient Maya civilisation. A scuba diver measures the length of the Sac Actun cave in Mexico, which is part of the Dos Ojos cavern system The Gran Acuifero Maya Project has been studying the caves off the eastern coast of Mexico o...