Although the pictures can't tell much, this was actually one of the highlights of our vacation. There are two wet caves just before the highway runs out on the north shore. The one right by the road is very small and boring. There is a upper wet cave that is reachable by a short trail. It contains a hidden phenomenon called the "Blue Room". It's a separate chamber where light, filtered through the cold fresh water, turns everything blue.
We had to swim about 20 feet to the back of the cave to enter the “Blue Room”. This fresh water was very deep and very cold. I waited a long time before jumping into it. I thinking seeing the “Blue Room” was not that big of a deal, but swimming in the ice cold water in a huge cave and going into a dark chamber was kind of thrilling.