From azure caverns to crystal-bedded lakes, find your inner explorer with these 21 photos and facts about the world's most incredible caves.

And what's killing Americans more than people in other developed nations.

Were these even supposed to be sexy?

This delightful series of drunk photos show what happens to each subject after one drink, then two, then three. You might be surprised.

Helen Meldahl takes selfies to a new level.

Find out which state might take the leap.

This incredible Titanic footage is your only chance to glimpse the doomed ship in action -- and see the waters where it sank.

A former army medic recounts his first time coming under fire, and how he escaped through a river of human feces.

See Marilyn before she became Marilyn.

River Monsters' Jeremy Wade on the weirdest river fish he's hauled in over the years, including giant piranhas and a fish that changes sex.