In 1748, the construction of the Viapori sea fortress (Sveaborg in Swedish, “The Castle of Sweden), which is currently known as Suomenlinna, began on the islands just off the coast of Helsinki.
Aastal 1748 hakati Helsingi rannikuvete saartele ehitama Viapori (rootsi k. Sveaborg, „Rootsi kindlus”) merekindlust, praegust Suomenlinna.