nesola: Jellyfish Lake, Republic of Palau, Micronesia. The jellyfish evolved in the lake without any predators, and over time grew vegetarian and lost their ability to sting. Their red color is a result of an algae diet. The water in the lake is salty.
Go kayaking (or canoeing) at night in the bioluminescent bay in Puerto Rico. It literally glows at night. go off the main island, if you go out of the bay it's a beach that you can only get to by kayak or swimming.