Not subscribed?

Mauna Kea is the tallest mountain in the world, but most of it is below the sea. Measured from its base on the ocean floor, it rises over 10,000 m (33,000 ft), significantly greater than the elevation of Mount Everest above sea level.

Location: Hawaii, centre of the Pacific

The Southern Ocean is the roughest ocean in the world, making tall, steep waves caused by strong wind and currents. It is also referred to as the Antarctic Ocean, the South Polar Ocean, and the Great Southern Ocean.

Location: all around Antarctica

The Challenger Deep in the Mariana Trench is the deepest place on Earth. It is 10,994 m below sea level.

Location: in the Pacific Ocean

This is the saltiest sea on Earth. The Dead Sea is even saltier, but is actually an inland lake rather than a true sea.

Location: between Africa and the Middle East

The Mid-Atlantic Ridge is an enormous mountain range that runs for over 10,000 miles but mostly under water!

Location: middle of the Atlantic Ocean

The Bay of Fundy has the biggest difference between the high and low tide of 16.3 m, which is taller than a 3 storey building!

Location: the east coast of Canada

The Great Barrier Reef is the largest coral habitat in the world, and the only living structure visible from space with the naked eye.

Location: off the east coast of Australia