My new idea is to visit all museums I can get access to using my SL card, with a few exceptions. Vaxholms fästning ("fästning" means "fort") is for example on a small island, prefectly visible from Vaxholm, but you have to take the boat there and that adds a cost. For international readers: an SL card is the ticket one uses to get around on trains, buses and the subway. It covers quite a large area, including other cities, so I have a lot to work on :)
I know that I have at least 20 museums left in the more or less centre of the city (which I can list), some more known than others, so now starts the search for museums I have not heard of before.
If you have any suggestions for museums I should visit, please hit me!