Cetina is a river in southern Croatia. It has a length of 101 km (63 mi) and its basin covers an area of 1,463 km2 (565 sq mi). From its source, Cetina descends from an elevation of 385 metres (1,263 ft) above sea level to the Adriatic Sea. It is the most water-rich river in Dalmatia.

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.