Aurora borealis (the northern lights) can be seen from the beginning of September until April. See our category
Aurora Borealis.
Reindeer Farm Sanila (accommodation, hiking, fishing in Sevettijärvi, 170 kilometers from Ivalo, bus connection from Rovaniemi):
http://www.sanila.fi/english/
Sampo Tours - Arctic Icebreaker (the World's only icebreaker for tourists, Kemi, this attraction is recommended by the bestseller book
1000 Places To See Before You Die):
http://www.sampotours.com
(Bus timetables Rovaniemi Railway Station - Arctic Circle (Santa Claus Village) - SantaPark - Arctic Circle - Rovaniemi Railway Station:
See
http://tourism.rovaniemi.fi/?deptid=6422 . At the bottom of that page you find an attachment file. Click it and you find those timetables.)
Snow Land (the possibility of overnight stays in snow igloos, the chance to make snow sculptures, the igloo restaurant with ice tables & starlit sky, the arctic disco, snow buildings, the horse farm, wedding ceremonies etc.):
http://www.snowland.fi
The Tourism Expert / Tourismus Team Europe TTE (almost all about Lapland, 10 languages, 12 categories: travelling, sightseeing, accommodation, activities, sports, events, maps, cities, regions etc.):
http://www.tte.ch/finland/lapland/
Welcome to national parks: