Archipelago Sea

By some definitions the largest archipelago in the world by number of islands, around 50,000, though a great many are very small and tightly clustered. It covers a rough triangle of 8,300 square kilometres between Mariehamn, Uusikaupunki and Hanko, of which only 2,000 are land. Counting depends entirely on what you call an island: 257 exceed a square kilometre, about 17,700 exceed half a hectare, and below that the rocks and skerries run past counting. The larger islands are inhabited and joined by ferries and bridges; the outer archipelago is mostly empty.