The Black Sea forms the eastern boundary of Bulgaria for a distance of 378 km – from Romania in the north to Turkey in the south. The depths have always been low in oxygen, very salty and practically no life can exist there. Only the thin upper layer, rich in oxygen and with a low salt content, is capable of sustaining life. It is the habitat of the Black Sea flora and fauna (fishes, dolphins, mussels, oysters, crayfish, seals).

     The Bulgarian Black Sea Coast has a mild, maritime climate. In summer the average daily duration of sunshine is more than 10 hours and in May and September it is at least 8 hours. There are a lot of mineral springs along the Bulgarian Black Sea Coast. A lot of settlements along the coast of Bulgaria were founded in the 7th - 6th century BC by the Ancient Greeks. At first the Greeks called the sea Axeinos, meaning "inhospitable" sea. Having settled down, they renamed it Euxinos – "hospitable". And since then it has been bearing its name.