Are you seeking a touristy walk through cave tour?
Or a down and dirty caving (spelunking) experience?
http://en.wikipedia.org/wiki/Caving
Big difference between the two.
From an ecological aspect, tourist caves (ie. Crystal Cave) are far better than having all those visitors exploring less known caves. While caving can be rewarding, the more people going through, often the more damage inflicted on the cave.
Ron