The islet of Stromsborg is located in Gamla Stan in the central part of Stockholm. Stromsborg in Swedish means Stream's Castle. The Stromsborgsbron Bridge connects Stromsborg with the other parts of Stockholm.
The islet of Stromsborg was previously known as the Stenskar meaning the Stone Skerry due to its rugged terrain. This small island is prominently marked in the map of Petrus Tillaeus. Queen Christina donated the islet of Stromsborg to her half brother as she mentioned in a letter in 1647. Formerly Stromsborg was considered to be very insignificant and it was not mentioned in the maps of Sweden. The island was not even properly explored.
In 1740 a merchant named Olofson Strom bought Stromsborg Island. It is believed that the merchant later constructed a house of stone resembling a castle in Stromsborg Island. It is supposed that the island of Stromsborg derived its name from the merchant's stone house or the stream. During this time one had to take a boat to reach Stromsborg from Stockholm.
For some years the head-quarter of the Swedish Sports Confederation was located at Stromsborg. The ground floor of this office building housed a popular restaurant. A dance hall was set up at Stromsborg Island in 1953. The top floors of the building housed some important offices. The building was renovated in 1996 and its former look was restored.