One cubic mile of seawater contains about 50 pounds of gold.
79
If Manhattan had the same population density as Alaska, there would only be 15 people living there.
138
Australia's Great Barrier Reef is 1,250 miles long!
45
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
More than 25% of the world's forests are in Siberia.
51
The Niagara Falls moves upstream at an average rate of about 295ft a century!
48
The Caspian Sea is also classed as the world's largest lake.
52