Jules Undersea Lodge, Key Largo, Florida, This is not a fancy 5 star, you have to scuba dive to your room. It is the first underwater hotel in the US.
三一 Underwater park in Austria. This is amazing! Really want to go Scuba diving again after seeing this.
Musha Cay, Bahamas
Maldives is the ultimate island destination. Many resorts are their own islands and feature personal cabanas attached by plank walkways over the water. See the famous bioluminescent phytoplankton beaches on Vaadhoo Island at night that look like an ocean of stars after dining on the sand at an award-winning restaurant.