This was a super cool place with an awesome tour. It's a limestone cave formed by water dripping through the cave ceiling. The icicle things from the roof are called stalactites. Stalagmites are the icicle looking things from the ground. When they meet they're called a column and sometimes you can get what's called a shawl.
Really awesome place to visit. For the photo with the reflections in the water I actually hung back so I could take the photo without any stray light from other people and it got eerily quiet. Really awesome experience!
Photography Tip: Try NOT to use a flash. Flash photography in a place like this will really ruin the ambiance. Use a higher ISO and slow down your shutter speed. Obviously tripod would be handy!
Highly recommended place to check out!