[tapland]

Aside from Vasa, the museums I'd recommend in Stockholm are:

The Royal Amory (https://livrustkammaren.se/en/home/)

A lot of old items from royalty and nobility. If you ever wanted to see how armor was deemed bullet-proof they have some dented chestplates that shows it off.

Swedish Army Museum (https://armemuseum.se/en/start/)

Army history from the 1500s and through the Cold War. Old collections of weapons, explanations of how huge armies were maintaned and fed and iirc they also have a huge old soviet missile.

[narrator]

The Abba museum is also a lot of fun. Yes, that Abba from the 70s.

[hericium]

A lot of Stockholm night clubs are partially ABBA museums

[wingerlang]

Conveniently just a short walk from VASA as far as I know.