10 of the tributaries flowing into the Amazon river are as big as the Mississippi river.
41
Due to gravitational effects, you weigh slightly less when the moon is directly overhead.
55
The city of Houston, Texas is built on a swamp and is slowly sinking!
89
The Caspian Sea is also classed as the world's largest lake.
52
The North Atlantic gets 2.5 centimetres (1in) wider every year.
119
Israel's Dead Sea is 1,312 feet below sea level.
48
One cubic mile of seawater contains about 50 pounds of gold.
79