The Neva Bay, also known as the Gulf of Kronstadt, is the easternmost part of the Gulf of Finland between Kotlin Island and the Neva River estuary where Saint Petersburg city centre is located. It has a surface area of 329 km. The entire bay has been separated from the Gulf of Finland by the 25 km long Saint Petersburg Dam. The area of water separated b…The Neva Bay, also known as the Gulf of Kronstadt, is the easternmost part of the Gulf of Finland between Kotlin Island and the Neva River estuary where Saint Petersburg city centre is located. It has a surface area of 329 km. The entire bay has been separated from the Gulf of Finland by the 25 km long Saint Petersburg Dam. The area of water separated by the dam is 380 km. The entire coastline is designated part of St. Petersburg rather than of Leningrad Oblast., the gulf freezes over for three to five months in winter. It receives the Neva and Narva rivers and the Saimaa Canal.