Hundreds of man-made caves dating back as far as the 9th Century lie waiting to be discovered underneath Nottingham, the city's archaeologist has said. The caves, which were used as dungeons ...

Walking along the terrain of the Phong Nha-Ke Bang National Park in Vietnam, you encounter a cave entrance. Stalagmites and stalactites pepper the mouth like awkward teeth, and clouds of steam ...

It is just one in probably hundreds of caves hidden in an “underground, undiscovered world”, according to the researchers. Countries are racing to establish a permanent human presence on the ...

If you're a thrill-seeking traveler, you may be interested in hiking through the largest cave in the world. You may be even ...