The city of Karlskrona is spread over 30 islands, Trossö being the main one; another is Saltö. The islet of Stumholmen was formerly property of the Navy and today it houses the National Naval Museum (Marinmuseum). Outside the city lies the archipelago of Karlskrona, the most southern of the Swedish archipelagos. Several islands are connected to the city by ferries.
Parts of the city have been declared a UNESCO World Heritage Site.
The main square of Karlskrona is the biggest in Scandinavia, and actually the second biggest in Europe, after the Red Square of Moscow.
The city was founded in 1680 when the Royal Swedish Navy was relocated from the Stockholm area to the Trossö island which had up until then been used chiefly for farming and grazing. At the time Sweden was the dominant military power in the Baltic sea region, but needed a better strategic location against Denmark, since southern parts of Sweden had been conquered only a few decades ago (see the Torstenson War). The Swedish fleet tended to get stuck in the ice during winter while located to Stockholm and was therefore moved south. The island had a very strategic position with short sailing distances to the German and Baltic provinces. The city name means Karl’s Crown in honour of King Karl XI of Sweden, the name being inspired by the name of the city Landskrona.
The city grew quickly and by 1750 Karlskrona had about 10,000 inhabitants. It was then one of the biggest cities in the country. Most of the baroque buildings from this era are still standing, which is why the city centre is architecturally uniform.
Every year in late July/early August a popular festival called The Sail takes place in the harbor of Karlskrona. Usually it is a place where families go to have something to eat and drink, and perhaps watch the sailing boats lined up at the pier. During the sail, the seascouts of Karlskrona will row a boat carrying torches along the docks while playing the national anthems for the visiting ships.
The old architecture together with the naval installations comprise the major tourist attractions of Karlskrona. The city has a pleasant atmosphere and is one of the highlights of south-east Sweden.