The longest cave in the world is the 'Mammoth Cave System' in the USA at 560,000 mtrs deep!
Every year, Alaska has about 5,000 earthquakes.
The North Atlantic gets 2.5 centimetres (1in) wider every year.
Israel's Dead Sea is 1,312 feet below sea level.
The Caspian Sea is also classed as the world's largest lake.