Adriatic Sea southeast, the Adriatic Sea connects to the Ionian Sea at the wide Strait of Otranto. The International Hydrographic Organization (IHO) defines the boundary between the Adriatic and the Ionian seas as a line running from the Butrinto River's mouth (latitude 39°44'N) in Albania to the Karagol Cape in Corfu, through this island to the Kephali Cape (these two capes are in latitude 39°45'N), and on to the Santa Maria di Leuca Cape (latitude 39°48'N). It extends from the northwest to the southeast and is wide. It covers and has a volume of . The Adriatic extends northwest from 40° to
Sea of Marmara , with dimensions .Its greatest depth is . The sea takes its name from Marmara Island, which is rich in sources of marble, from the Greek "μάρμαρον" ("marmaron"), "marble". The sea's ancient Greek name "Propontis" derives from "pro-" (before) and "pontos" (sea), deriving from the fact that the Greeks sailed through it to reach the Black Sea, "Pontos". In Greek mythology, a storm on Propontis brought the Argonauts back to an island they had left, precipitating a battle where either Jason or Heracles killed King Cyzicus, who mistook them for his Pelasgian enemies. The surface salinity of the sea averages