Legends of names of the city parts - Kamenny ostrov (Stony Island)
In the middle of Small Nevka river, opposite to southern coast of island, the huge stone from which and the island name has gone towered.
Long time inhabitants of Petersburg considered that their city is located on 101 island. It was exactly valid, but this figure was not called in question and check within hundred years.
Meanwhile in the process of a city building their quantity was reduced and under the last data there were 42 islands. It was promoted by many factors, both natural, and connected with human activity. The islands were washed away, also exhaust to winds and not strengthened by quays and dams.
Among remained - three are especially favourite by Petersburgers. They name it Islands though everyone of them has own name - Yelagin, Krestovsky and Stone. Stone island - the most northern of them, and a legend about an origin of its name historians link with those age-old times when all adjoining to the Big Nevka area , including Old and New villages, named Kamenkoj, as here there were many stones left by ancient glaciers.
By the way, on the Swedish cards of a XVII-th century it is designated as Kivi-saari that in a literal translation means exactly Stone island.
Source: Three centuries of St.Petersburg: Encyclopaedia