More than a dozen men have stood on the surface of the moon, but only three have been to Challenger Deep in the Marianas Trench, the deepest known spot in the ocean.
17
If Antarctica's ice sheets melted, the worlds oceans would rise by 60 to 65 metres (200 - 210ft) - everywhere
181
There was once an undersea post office in the Bahamas.
241
Two dogs were among the Titanic survivors.
262
The Titanic is about as long as the Empire State building is tall.
174
The North Atlantic gets 2.5 centimetres (1in) wider every year.
119
The Caspian Sea is also classed as the world's largest lake.
52