I couldn't help but think of the movie 'Lord of the Rings' as we entered the caves...
It was exciting knowing that you are entering a place where an entire mountain is on top of and around you.
The caverns were completely dark if not for the beams of light from the boats.
The cave went on and on and the trip only took a short mile or so into the Underground. The river is still accessible for those of you thrill seekers that want to venture deeper in but a special permit is then required to proceed any further.
This last picture gives you an idea of the traffic inside the Underground caves. The light ahead is how close the boat was ahead of us.