Canada has more lakes than the rest of the world combined, holding about 9% of the world's fresh surface water.

Urban populations now exceed rural populations worldwide.

The Great Rift Valley in Africa may eventually split the continent in two, forming a new ocean in millions of years.

The Silk Road connected Asia and Europe for centuries.

The longest river in the world is often considered to be the Nile.

The first forests appeared during the Devonian period.

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

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

The Nile Delta is sinking — it's being weighed down by sediment and eroded by rising seas.