Santa Claus' Village on the Arctic Circle in Rovaniemi in Lapland (Finnish Lapland) is a nice place, open every day of the year, where you can do all kinds of fun things, like meeting Santa Claus himself, or visiting Santa Claus' official Main Post Office, where he receives hundreds of thousands of letters every year.

Useful links:
The official www-site of the Santa Claus Village in Rovaniemi in Finland: www.santaclausvillage.info
Rovaniemi in Lapland in Finland official tourism information