At the very end of one of Oslo's metro lines lies the district of Mortensrud. A quick Google search will bring up all sorts of information that does little justice to Mortensrud's image. House prices are considerably lower there, and the number of police reports is significantly higher than the Norwegian average. Having lived in Amsterdam for a long time, it has taught me not to be swayed by such information. And that's why I believe it's worth having more people visit Mortensrud, if only to experience the magnificent church that was completed there in 2002. Designed by Jan Olav Jensen and Børre Skodvin, this architectural masterpiece is truly a work of art. As a fervent admirer of architecture, I consider it to be one of the, if not THE most beautiful building in Oslo.
If the church atmosphere hasn't managed to cleanse your soul just yet, then the nearby resort hotel called 'The Well' is just a stone's throw away. For a thorough detox from urban life, this is the finest haven I can imagine. A hammam, sauna, luxurious swimming pool, a Japanese onsen—the list goes on. I believe you could easily dedicate two days to this blissful retreat as it can easily be called the best spa in Norway.
In addition, a visit to The Well serves as anthropological fieldwork, allowing you to observe the very special 'luxury-seeking-Oslo breed' in all its diverse plumage. I would suggest this to be the grande finale to your visit to Oslo/Norway. Check here for availability.