From the air, it looks like an ink spill in turquoise water, a perfect circle that seems to drop straight into the planet. For decades, Belize’s Great Blue Hole has pulled in explorers, filmmakers and ...

For people with "thalassophobia," or the fear of deep bodies of water, blue holes are something out of a nightmare. These massive vertical caves open up in the shallow waters near coastlines, but blue ...

Forbes contributors publish independent expert analyses and insights. I write about biodiversity and the hidden quirks of the natural world. Sinkholes are natural depressions that form when rock ...