Which natural feature is the Cayman Islands famous for?

The Great Blue Hole is a prominent natural feature that showcases the stunning marine environment surrounding the Cayman Islands. This large underwater sinkhole, which is part of the Belize Barrier Reef Reserve System, attracts divers and tourists from all over the world due to its unique geological structure and rich biodiversity. The Great Blue Hole is renowned for its deep blue color and the diverse marine life that resides within it, including various species of fish, corals, and other sea creatures. Its popularity in marine tourism highlights the Cayman Islands' reputation as a premier diving destination, making it an iconic symbol of the area.

The other options, while notable in their own rights, do not specifically relate to the Cayman Islands. The Bermuda Triangle is a region associated with various maritime mysteries but is not unique to the Cayman Islands. The Everglades are a vast wetland ecosystem located in Florida, far from the Caribbean. The Amazon River is the largest river in South America, completely unrelated to the geographic features of the Cayman Islands. Thus, the Great Blue Hole stands out as the defining natural feature associated with this Caribbean territory.