During the summer, all 10 Swedish royal palaces and their museums, parks, chapels, shops and cafés will be open.

Take a trip to the royal palaces and visit the locations that have played central roles in Sweden's royal history.
The palaces are home to four centuries of art and history, as well as some of the country's best-preserved interiors.

More info here:

https://www.kungahuset.se/royalcourt/latestnews/latestnews/summerattheroyalpalaces.5.2cf3d1716b924e7fde36e3.html