This book focuses on the Adriatic Sea, which is part of the Mediterranean. It includes 700 articles on the hydrographic and geographic objects, hydrological features and biological resources, as well as the administrative-territorial units of the Adriatic countries, briefly describing significant natural objects like islands, peninsulas, bays, rivers, mountains, and their geographical peculiarities. It also covers the economy, culture and history, cities, ports, international agreements, research institutions and the activities of outstanding scientists, researchers, and travelers. Lastly, it provides a chronology of the main historical events that have become significant landmarks in the history of discovery and exploration of the Adriatic Sea, from the 625 B.C. to the present day.