The Great Barrier Reef is the largest coral reef in the world—measuring 1250 miles (2010 kilometers) in length and 45 miles (72 kilometers) in width at its widest point. The particular section of the reef in this picture is located northwest of Cape Melville just off of the eastern coast of the Cape York Peninsula in Queensland. Hundreds of varieties of coral grow on the Great Barrier Reef. The largest reef (bottom center) in the picture is Hedge Reef and Magpie Reef, the second largest reef in the image, is visible slightly northwest of Hedge Reef. The three roughly circular, dark-centered features along the left side of the image are small tropical islands that are part of the Claremont Isles. The Great Barrier Reef is recognized as a World Heritage Site and, as such, national as well as international ethical guidelines to protect the reef system are being implemented.