Karlskrona is a world heritage site as a military town. But I still think Brandaholm is most beautiful. A colonial cottage area located on one of Staun's many islands, but which hardly has anything to do with world heritage.
Brandaholm is located on Dragso. The area consists of 45 cute cottages that almost look like they are standing on top of each other and this must be Sweden's cutest cottage area by far. These red cottages by the sea also often get to represent the whole of Sweden on puzzles, book covers and souvenirs. No wonder.
Karlskrona is generally a very special place in that the entire city has been laid out on islands in the archipelago. Moreover, as late as the 17th century. And for the sake of the fleet. Trosso is called the most central island, but Staun consists of many more islands. Some particularly beautiful places in Karlskrona are Stortorget, Stumholmen with the Marine Museum, Bjorkholmen and Ekholmen. I also really like the old hot bath house inside Trosso.
Overall, the whole of Blekinge is very beautiful, but in this list I have decided not to count entire landscapes as a place. Although Blekinge is so small that you could almost do it.