One cubic mile of seawater contains about 50 pounds of gold.
79
The longest cave in the world is the 'Mammoth Cave System' in the USA at 560,000 mtrs deep!
63
Mexico City is built on top of an underground resevoir!
47
Europe is the only continent without a desert.
62
Every year, Alaska has about 5,000 earthquakes.
31
The Niagara Falls moves upstream at an average rate of about 295ft a century!
48
The Sahara desert expands at about 1km per month.
90
