1. Oslo's Narvisen skating rink is located at Spikersuppa/Karl Johan Street in the center of Oslo (street map of Oslo). This skating rink is open to everyone, daily from December to March.
You can't skate from 4-5 pm while the ice is being renewed (and leave hockey equipment at home) but there is a nice kiosk offering hot and cold snacks and drinks for your off-ice time.
(If you need skates at the Narvisen Skating Rink, it will cost NOK 45 for adults and NOK 30 for kids. However, you'll receive a discount with the Oslo Pass.)
2. Another free ice skating rink can be found inside Frogner Stadium, which is located at Middelthunsgate 26 in western Oslo. You can get a free street map of Oslo here.
Ice prep takes place from 2-3 pm at this place, after which the skating rink is open to the public.
At Frogner Stadium, you can even sign up for fun ice skating classes with the ice skating club of Oslo (Skøiteklub).
This ice skating rink in Oslo does not allow hockey equipment on the ice on Mondays, Saturdays and Sundays from 6-8 pm. Ice skate rentals are available here as well.
