Helsinki, Swedish Helsingfors, capital of Finland. It is the leading seaport and industrial city of the nation. Helsinki lies in the far south of the country, on a peninsula that is fringed by fine natural harbours and that protrudes into the Gulf of Finland. It is the most northerly of continental European capitals. It is often called the “white city of the north” because many of its buildings are constructed of a local light-coloured granite.