Natural Locations - real life examples

[Umbra]

I would like examples of natural locations from all around the world for inspiration and images.

Watched a documentary on the cenotes of the Yucatan. Great dungeon setting.

eg http://www.healtoronto.com/biketours/cenote.html
eg http://www.yucatantoday.com/destinations/eng-cenotes.htm

And years ago, I think it was in Dragon, there was an article on the underground cities in Turkey...ah! the author has put the article online (thanks be to Google).

http://www.allenvarney.com/av_turkey.html

Other suggestions...
(if there are other threads you know about link 'em in. a search revealed nothing but my enworld searches seem to let me down a lot.

 

[WayneLigon]

More on The Cave Cities of Cappadocia, Turkey
The Karst Mountains of China (I think you see this same area in Willow)

 

[Jdvn1]

I add to this at odd intervals...

http://www.enworld.org/showthread.php?t=140218