This chapter studies the basic physiographical and oceanographical peculiarities of the Adriatic Sea. It describes in brief the islands, coasts, relief, and bottom sediments. It provides the general hydrometeorological characteristics (wind, waves, and precipitations). Special attention is focused on the hydrological regime of the sea (water masses, currents, temperature, and salinity). In addition, it dwells on the present-day development of the Adriatic Sea, i.e., tourism, fishery, mariculture, hydrocarbon production, and shipping.