The book is dedicated to the Ionian Sea, which is part of the Mediterranean. The encyclopedia contains about 600 articles on the hydrographic and geographic objects, hydrological features of the sea, biological resources, as well as administrative-territorial units of the Ionian countries. The most significant natural objects like islands, peninsulas, bays, rivers, mountains, their geographical peculiarities are briefly described as well as economy, culture and history, cities, ports, international agreements, research institutions, activities of outstanding scientists, researchers, travelers are presented in the publication. The chronology of the main historical events that have become significant landmarks in the history of discovery and exploration of the Ionian Sea from the 31 B.C. to the present day is given.

Prof. Dr. Igor S. Zonn - Doctor of Geography, full member of the Russian Academy of Natural Sciences, Honored Meliorator of the Russian Federation, General Director of the Engineering Research and Production Center for Land Reclamation, Water Management and Ecology “Soyuzvodproekt" (Moscow), member of the editorial board of the international Journal «Problems of desert development» (Turkmenistan), member of the editorial board of the Journal “Arid Ecosystems", “Post-Soviet Issues" (Russia) Studio Marina (Montenegro). The winner of the Underwater World national award. Author of over 450 scientific articles and 50 monographs, author of the encyclopedias of the Black, Caspian, Aral, Japan, Okhotsk, Bering, Barents, White, Kara, Laptev, East Siberian, Chukchi, Baltic, Adriatic, Ionian, Aegean seas, Arctic Ocean and Danube River, Desert and Desertification published in 2004-2019 in publishing houses "International Relations" (Russia).