Trunk Bay, St John, US Virgin Islands

Trunk Bay in Virgin Islands National Park on St John is home to the world's first underwater snorkelling trail — established by the National Park Service — with submerged plaques identifying coral and fish species along a 225-metre route. The sheltered cove of powdery white sand is surrounded by tropical forest and accessible via road through the national park. National Geographic named it one of the world's ten most beautiful beaches and it receives over 100,000 visitors annually.