Vistula Lagoon
The Vistula Lagoon is a brackish water lagoon on the Baltic Sea roughly 90 kilometres (56 mi) long, 10 to 24 kilometres (6 to 15 mi) wide, and up to 5 metres (17 ft) deep, separated from the Gdańsk Bay by the Vistula Spit. It is split between Poland and Russia (Kaliningrad exclave).