Other Stockholm Churches
Perhaps Stockholm doesn't have as many ancient churches as some of the other major European cities, but it is nonetheless a stunning city- one of the prettiest in Europe.  It sits on 14 major islands and is a very pleasant place to stay.  Outside Gamla Stan it's a bit newer, but there are still some nice churches just north of the old island.  Go to the top of the tower in the City Hall (Rådhus) to get a great view of Gamla Stan and surrounding environs (it is on the mainland northwest of Gamla Stan).