Sea of Azov
Important cities at the shore of the sea are  Berdjansk, Mariupol, Taganrog, Jeisk.  A few kilometers up the course of the Don, there's Rostov-on-Don, and the city of Azov in the estuary of the Don river. Berdjansk, and Mariupol are in Ukraine; the other cities are in Russia. The Crimean peninsula is officially part of Ukraine, but occupied by Russia.