The longest cave in the world is the 'Mammoth Cave System' in the USA at 560,000 mtrs deep!
63
10 of the tributaries flowing into the Amazon river are as big as the Mississippi river.
41
More than 25% of the world's forests are in Siberia.
51
The average ice berg weighs 20,000,000 tons!
54
The Amazon rainforest produces more than 20% the world's oxygen supply.
182
There are more than 50,000 earthquakes throughout the world every year!
47
The Sahara desert expands at about 1km per month.
90
The city of Houston, Texas is built on a swamp and is slowly sinking!
89