Used for water distribution, the Delaware Aqueduct in New York, USA is the longest tunnel in the world (as of 2010). Drilled through solid rock, it reaches a staggering 137 kilometres (85 miles) in length. More tunnel facts.

Children laugh about 400 times a day, while adults laugh on average only 15 times a day.

The winter of 1932 was so cold that Niagara Falls froze completely solid.

AMAZING FACTS