![](http://www.alamy.com/thumbs/6/9B162230-0D6F-4D32-933B-D27867A09535/AEAYCT.jpg)
A snorkeler looks down into the dark depths below in a natural blue hole, formed as the roof of a cave collapsed eons ago in the Republic of Palau.
Size: 4800px × 7200px
Location: Palau, Micronesia
Photo credit: © Ethan Daniels / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: acidification, adventure, animals, beautiful, biodiversity, blue, change, climate, colorful, conservation, coral, diversity, diving, ecosystem, environment, erosion, fish, geology, habitat, healthy, hole, island, islands, landscape, micronesia, natural, nature, niche, ocean, pacific, palau, reef, remote, research, rock, scenery, scenic, science, scuba, sea, seascape, sink, snorkeling, tourism, travel, tropical, tropics, underwater, vacation, water, wild, wilderness, wildlife