The world's deepest underwater sinkhole in the waters of Chetumal Bay between Mexico and Belize remains shrouded in mystery after researchers reported they have yet to determine its full depth.

Norway’s Rogfast is an exceptional engineering feat, opening a route for drivers deep below the North Sea. We went down to ...

Near the Chinese city-province of Chongqing lies a natural wonder of truly epic proportions. The Xiaozhai Tiankeng is the deepest sinkhole in the world, where even skyscrapers would disappear. But the ...