In Vietnam, the worlds longest cave

[Sarge]

Pretty cool

http://ngm.nationalgeographic.com/2011/01/largest-cave/peter-photography

 

[Goaldeje]

That is awesome. Nice find.

But I thought the Journey to the Center of the Earth started in Iceland?

 

[Miles Monroe]

I love the last pic of the people climbing through the giant crystals.

 

[Elephant]

I love the last pic of the people climbing through the giant crystals.

I saw teasers on those crystals that had me intrigued, but never got the chance to see the show.

http://news.nationalgeographic.com/news/2007/04/photogalleries/giant-crystals-cave/

Apparently you can only go so far in those caves for brief periods of time because of the heat plus the humidity is said to be suffocating.