Vuosaari is a neighbourhood in the city of Helsinki, Finland. It is located by the sea in East Helsinki and with its area of 15.38 km is geographically the largest district in the city. Vuosaari is one of the fastest-growing areas in Helsinki. The number of inhabitants has been increasing rapidly since early 1990s and it continues to grow as new residential areas are beiā¦Vuosaari is a neighbourhood in the city of Helsinki, Finland. It is located by the sea in East Helsinki and with its area of 15.38 km is geographically the largest district in the city. Vuosaari is one of the fastest-growing areas in Helsinki. The number of inhabitants has been increasing rapidly since early 1990s and it continues to grow as new residential areas are being built.