The water and the full moon
Caves with water are beautiful places that connect you 100% with nature. Without a doubt, you should meet them at some point in your life, but make sure it is not on a full moon night. The moon is a great moderator of tides, and when it is full, it causes the water to go down.
Until then, everything is beautiful; the problem is that when the moon goes, the water will rise again, and you could be trapped in it. Something like this happened to a group of Thai students, and they had to be rescued from the cave they were in.