10 of the tributaries flowing into the Amazon river are as big as the Mississippi river.
41
Venice Island was built on a foundation of tree trunks. 1200 years later, those same trunks still support almost all of central Venice.
8
It takes a drop of ocean water more than 1,000 years to circulate around the world.
61
The North Atlantic gets 2.5 centimetres (1in) wider every year.
119
The water between India and Sri Lanka is only 3-30 feet deep and was purportedly passable on foot until 1480 AD when a cyclone moved some sand around.
1
An earthquake on Dec. 16, 1811 caused parts of the Mississippi River to flow backwards.
243
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
The Caspian Sea is also classed as the world's largest lake.
52