Countries with extremely high tax rates sometimes collect less revenue than countries with moderate tax rates.

The Colosseum in Rome demonstrates advanced ancient engineering.

The shortest commercial flight in the world is between two Scottish islands — it lasts about 90 seconds.

Mount Everest is not the closest point to space — due to Earth's equatorial bulge, Mount Chimborazo in Ecuador is actually closest to the stars.

The Colosseum in Rome could hold up to 80,000 spectators — comparable to a modern NFL stadium.

The Caspian Sea is technically the world's largest lake, covering 371,000 square kilometers.

More people live in Tokyo than in the entire country of Canada.

The Panama Canal connects the Atlantic and Pacific Oceans.

The Earth is slightly flattened at the poles.