The city of Houston, Texas is built on a swamp and is slowly sinking!
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A waterfall known as The Devil's Kettle empties water into a hole and nobody knows where it ends up!
18
The Dallas/Ft. Worth airport is larger than New York City's Manhattan Island.
62
Even Antarctica has an area code. It's 672.
58
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
Check your map! The Pacific entrance of the Panama Canal is farther East than the Atlantic entrance.
40
Connecticut and Rhode Island never ratified the 18th Amendment (Prohibition).
25
The longest cave in the world is the 'Mammoth Cave System' in the USA at 560,000 mtrs deep!
63