Great Barrier Reef
The Great Barrier Reef is the world's longest coral reef system, stretching around 1,430 miles (2,200 km) along the east coast of Australia. It is made up of 2,900 separate reefs, each made up of limestone deposited from the calcareous skeletons of countless tiny sea creatures. It provides a rich environment for aquatic life; six out of seven of the world’s marine turtles, 1,500 out of 13,000 species of fish, 500 types of seaweed, 360 varieties of coral and 125 species of sharks and rays live in the waters of the reef.
The Great Barrier Reef is home to a wide variety of sea life. Among them are some of the most dangerous creatures in God's creation, such as Chironex fleckeri, the infamous box jellyfish. There are so many dangerous creatures in the reef, that the Australian government places nets along their beaches to protect swimmers from the sea life.
Scientific investigation has shown that the reef could have grown to its present extent in the time since Abraham was alive. Growth rate analysis has shown that the oldest reef on earth is 4,200 years old. 
A very interesting fact is that the Great Barrier Reef can be seen from space, it being so large.