While in Oslo my husband and I visited the Resistance Museum which was situated near the Castle on the hill overlooking the harbour. There was a small fee but as we had the Oslo pass the entry was free with the pass.
There was a seating area at the front of the museum behind the reception desk. Books and other articles were on display. A toilet was available for use in this area.
I was not aware of the role Norway played in World War II. It was amazing to read (a lot were only in Norwegian but some articles were translated into English) about the heroic deeds undertaken by the local people leading up to and during the five years of occupation of Norway.
Radio broadcasts could be listened to and news clippings were on boards and behind glass cabinets to read. There were many artifacts from the period. Today, it would be hard to imagine how people could survive in the conditions that they did. The museum was well laid out and it was possible to continue in a line and not double back without missing any of the displays.
When in Oslo this museum would be one of the first places to visit to get the feel of the city and the country during occupation. Be prepared to spend at least an hour or two going through and round the exhibits.