The longest cave in the world is the 'Mammoth Cave System' in the USA at 560,000 mtrs deep!
Niagara Falls moving upstream
The Niagara Falls moves upstream at an average rate of about 295ft a century!
More Geography Facts
Amazon rainforest oxygen supply
The Amazon rainforest produces more than 20% the world's oxygen supply.
Gold in seawater
One cubic mile of seawater contains about 50 pounds of gold.