Palau's famed "Rock Islands" are a collection of rounded, foliage-covered isles which seem to float above the surface of the water. This collection of mushroom-shaped islets is largely uninhabited and is located in a large lagoon that harbors one of the world's greatest concentrations of corals, fish and other marine life. A boat trip through them will reveal a number of magnificent white sand beach hideaways perfect for a secluded picnic or adventurous overnight stay. Below the water's surface, divers and snorkelers are treated to a diverse technicolor paradise of fabulous drop-offs, blue holes, breathtaking reefs, crystal caves and World War II wrecks. The diving is nothing less than phenomenal – and best of all, much of the action (including WWII wreck) is in water shallow enough for snorkeling. Of course, it helps when you can clearly see the bottom 50 feet down. Rock Islands is a favorite destination, particularly a 35-foot high sea cavern known as Cathedral Cave.