Skansen open air museum
It seems to become our new tradition to visit a zoo, now that we are traveling with a toddler. Animals and children...always a win win.
But Skansen is not really a zoo. It's primarily an open air museum conserving the traditional agricultural Swedish society, reconstructing farmland buildings from all over the country including re-enacting and including native wild and less wild animals. (cfr Bokrijk for Belgians or Fort Steel for BC - Canadian readers).
Skansen is on one of the bigger islands right next to downtown (the same where the Vasa museum is and the amusement park Gruna Lund...so quite a good touristic destination).
Skansen Aquarium right next to the open air museum...which funny /confusingly enough has few very big & fun monkey exhibitions