The second-largest island in Greece is small on the crowds but big when it comes to beaches, mountain trails, healing waters, ...

Dead zones appear annually, May through September, in the Gulf of Mexico, after tons of nutrients from fertilizer use and sewage in the Mississippi watershed wash downstream into the Gulf.

When hundreds of eerily perfect circles were discovered on the bottom of the Mediterranean Sea, theories abounded about what they could mean. Four years of underwater research revealed a lost world.