Oahu, Eternity Beach is a bit of a hike down to get to it but you can also see it from the street. There you will often see giant sea turtles swimming with the human swimmers. This is one of my favorite places in the world.
Diamond Head, Oahu, Hawaii is the name of a volcanic tuff cone on the Hawaiian island of O'ahu. Its English name was given by British sailors in the century, who mistook calcite crystals on the adjacent beach for diamonds. Hawaii is the state.