Going through the Bayano Caves was an amazing experience. Our guide was delightful, he arrived on time, was very knowledgable, and even pulled over once so we could look at some monkeys in a tree. This tour stopped at a wonderful family cabin where we left some of our things while in the cave and have a wonderful fish lunch after. The cave itself was really interesting and beautiful, though nowhere is more beautiful than the canyon on the other side. Nobody else was signed up for the tour yesterday, so it ended up being a private tour for my husband and I, which was really nice.
Note - this tour is not for everyone. It requires a fair bit of physical fitness and a little bravery. You need to be able to navigate over invisible rocks underwater, do a small amount of rock climbing, and you may have to swim a bit. It is worth it, but if you have any mobility issues at all, this likely isn't your best activity.