Gdańsk Bay or the Gulf of Gdańsk is a southeastern bay of the Baltic Sea. It is named after the adjacent port city of Gdańsk in Poland. The western part of Gulf of Gdańsk is formed by the shallow waters of the Bay of Puck. The southeastern part is the Vistula Lagoon, separated by the Vistula Spit and connected to the open sea by the Strait of Baltiysk.