I'm doing around three weeks in Germany, Denmark, Sweden, and Norway (kind of a rushed trip, but oh well!), and I've noticed that a lot of the places I'm going (specifically Arhus, Copenhagen, Stockholm, Oslo and Bergen) have open air heritage museums with regional buildings and/or a viking ship museum of some kind.
Now, I am interested in things like half timber architecture, but I think if I go to the open air museum/viking ship of every single city I might be sick of it/out of more money than necessary at the end. So, does anyone have any recommendations for which ones are the don't miss versions?