This paper is intended as a short summary of 20 years of research on the Adriatic Sea carried out by the Oceanography Department of IRPeM-CNR. The objective is to give a general overview of the sea and describe the environment in which anchovies live. The Adriatic Sea is a narrow basin elongated from north-west to south-east for about 800 km with a maximum width of 200 km at Bari and a minimum width of 100 km in front of Rimini. It communicates with the Ionian Sea through the Otranto straits (74 km wide and 800 m sill depth). It is the most continental sub-basin of the Mediterranean, defined between two mountain chains: the Apennins to the west side and the Dinaric Alps and Balkans to the east. The Adriatic can be divided into three distinct sub-basins: Northern, Middle and Southern. Due to the geographical position, its orography and bathymetry, the Adriatic Sea hydrography is strongly influenced by meteorological conditions, particularly in the north. Climatologically, temperature variations greater than 20°C are observed between winter and summer, and about 8 °C from north to south in winter, as well as a salinity gradient of about 3 psu (practical salinity unit) between the western coastal water and the offshore water. Interannual variability has been evident from the first systematic oceanographic observations of this sea and is remarkable. There are three principal water masses in the Adriatic Sea: the Adriatic Surface Water (AdSW), the Levantine Intermediate Water (LIW) and the Adriatic Deep Water (AdDW) (every sub-basin has its own characteristic deep water). The general circulation is cyclonic with a flow towards the northwest along the eastern side and a return flow towards the southeast along the western side. The circulation in the three sub-basins is often dominated by their own cyclonic gyres that vary in intensity according to the season. The sub-gyre of the southern Adriatic tends to persist throughout the year. The sub-gyre of the middle Adriatic is more pronounced in summer and autumn, while in the north, a cyclonic gyre is evident, in front of the Po river mouth, only in autumn.