Gulf of Koper Gulf of Koper The Gulf of Koper or Koper Bay (, , ) is located in the northern part of the Adriatic Sea, and is a part of the Gulf of Trieste. The gulf, named after the city of Koper, is part of the Slovene Riviera and is entirely located in Slovenian territory. Crossed by the river Rižana, it is 18 km² large and spans from Debeli Rtič, next to the borders with the Italian town of Muggia; to Rt Madona, a cape in the town of Piran, that is also the northernmost point of the Gulf of Piran. The
Baltic Sea Gulf of Bothnia, of which the northernmost part is the Bay of Bothnia or Bothnian Bay. The more rounded southern basin of the gulf is called Bothnian Sea and immediately to the south of it lies the Sea of Åland. The Gulf of Finland connects the Baltic Sea with Saint Petersburg. The Gulf of Riga lies between the Latvian capital city of Riga and the Estonian island of Saaremaa. The Northern Baltic Sea lies between the Stockholm area, southwestern Finland and Estonia. The Western and Eastern Gotland Basins form the major parts of the Central Baltic Sea or Baltic proper.