Scandinavia is great for children. A lot of what is fun for kids is just enjoying the great outdoors- swimming and fishing in the lakes and the sea, bicycling, hiking, and skiing and skating in the winter. There are of course also theme parks, play areas and museums with lots to offer children. If you are planning on visiting the Nordic countries with your kids, have a look at the pages listed here where I have recommended some of the places that I have enjoyed with my two small kids.
Our favourite places so far are: Junibacken in Stockholm (I could go on the Story train again and again), Moomin World in Naatali, Finland- only open in the summer but it’s exactly how you imagine Moomin Valley, Tivoli Gardens in Copenhagen which has beautiful grounds and rides for all ages and Gotland (what a stunning island- so beautiful and so much to explore for children and adults alike).