Do something on one of their famous landmarks. That should be simple. I know we knew about landmarks all over when I was around his age, or at least we did quick coverage on some.
Example:
"
Kalmar Castle is a legendary Swedish landmark whose history can be traced to as far as 800 years. It was originally built as protection against pirates and other enemies coming in from the sea. Tagged as “The Key to the Kingdom”, the castle played an essential part in Nordic politics. In 1397, it was the site of the signing of the Union of Kalmar wherein Sweden, Denmark, and Norway were united under one crown. In the 16th century, the fortress was transformed into a Renaissance Palace under the direction of the Wasa Kings Erik XIV and Johan III. Today, it stands as one of the best preserved renaissance castles in Europe. A visit to Kalmar is not complete without stopping by the castle."
Or this
"Skansen on the island of Djurgården is the world’s largest open-air museum and over 150 buildings were brought here from all over Sweden to bring it to life. It is a living, working, functional Sweden of yesteryear with glass foundries, a bakery, farms, a Sami village, a town centre, shops etc. It also has a zoo, an aquarium, a children’s zoo and old-style amusement park. Skansen is worth a day of your time. We think your kids will agree."
A museum could be cool and easy to do by just making pieces that you could find in that museum.