Spelunking

Sure, it might seem a tad less extreme than the rest at first glance, but when you take a look at all the serious risks involve--including hypothermia, dangerous gases, disease, cave-ins, and flooding, you might think again.


Caving--also referred to as spelunking in the United States and potholing in the UK--involves the exploration of cave systems. Participants frequently find themselves in wet, cold, dark, and extremely tiny spaces--often with no clear way to get out. This sure isn't a sport for anyone prone to claustrophobia!


-Picture courtesy Thinkstock-