Lošinj is a Croatian island in the northern Adriatic Sea, in the Kvarner Gulf. It is almost due south of the city of Rijeka and part of the Primorje-Gorski Kotar County.

The Adriatic Sea is a body of water separating the Italian Peninsula from the Balkan Peninsula. The Adriatic is the northernmost arm of the Mediterranean Sea, extending from the Strait of Otranto to the northwest and the Po Valley. The countries with coasts on the Adriatic are Albania, Bosnia and Herzegovina, Croatia, Italy, Montenegro, and Slovenia.