Spelunking is a terminology for cave explorations and is believed to come from this story.

The origin of spelunking can be found at the turn of the century when a man named Randolf Skinner disappeared in a cave in western South Dakota.

A search party was sent in to look for Skinner's body. But everyone decided they were really liked wandering through the caves. So they gave up on the search, seeing no one really liked Randolf anyway, got drunk and the rescue party themselves got lost and died. The word "spelunking" is actually German, "schpee lunkur" which means "he who searches for cadavers in dark places and gets intoxicated and dies."

http://media.www.gsusignal.com/media/storage/paper924/news/2001/10/16/Perspectiv...

Spelunking, the hobby or practice of exploring caves has an association to speleology, the scientific study of caves.
http://en.wikipedia.org/wiki/Speleology

Spelunking is a kind of caving but usually done in an inferior manner.

The term was coined by Clay Perry.