We are constantly amazed by cool people doing awesome activities in spectacular places. i.e. below video:

Caves are so fascinating for so many reasons: they are mysterious, immortal, majestic, and, most of all, limitlessly explorable.  Winching around the flat waters of this 'grotto' is just another means of exploring a tremendous natural wonder.

I was lucky enough to do some underground 'blackwater' rafting in New Zealand a few years ago and it was an experience of a lifetime.  Turn your headlamp off for a bit and all you can see are millions of glow worms like stars in a perfect night sky.

Descending into the abyss.

Of course, you have to get into the caves somehow.  In New Zealand the journey started with a 300 foot rappel into pitch black darkness.

Lebanon wakeboarding video spotted in this BBC Article.