It is part of the Gulf of Venice and is shared by Italy, Slovenia and Croatia.
With the exception of flat islets blocking the entrance to Marano-Grado lagoon, there are no islands in the gulf.
Tides in the gulf are among the largest in the Adriatic Sea, but nevertheless do not usually exceed 60 centimetres (24 in).
Its most prominent features are: The entire Slovenian coastline is located on the Gulf of Trieste.
[2] Towns along the coastline include (from east to west) Koper, Izola, and Piran.