In Finland, you can send a letter to Santa Claus with only this address: Joulupukki 99999 Korvatunturi Where "Joulupukki" is the Finnish name for Santa, and "Korvatunturi" is the mountain where he supposedly lives. Postal code 99999 was reserved for this purpose.
>and "Korvatunturi" is the mountain where he supposedly lives... But then the Post Office nearest that mountain would have to re-direct all those letters to the North Pole... where he actually lives!
He also has a tourist trap at Rovaniemi (a city in Lapland) where the letters actually end up.