The Copper door is undoubtedly the prettiest Airbnb, Syl and I have been to ever. Jannike is amazingly great as a host. It is very close to the central station and the metro train is just 4 mins walk away making it extremely easy to travel around. And everything about the mattress is true !!!. We slept like a baby. There is a public swimming pool just 15 mins away which is definitely worth a visit on a warm sunny day. Adjacent to the pool is an ice rink available during the winters for ice skating. Getting an oslo pass is highly beneficial as it allows unlimited travel through public transport as well as a lot of tourist destinations. The room has everything you would probably need, along with some tips and information about some of the best places to visit and restaurants to be tried out.
Highly recommend Jannike's Place (the copper door) to everyone visiting oslo.