Trebišnjica

alt=Trebišnjica in Trebinje|thumb|Trebišnjica in Trebinje The Trebišnjica () is a river in Bosnia and Herzegovina, and the right tributary of the Neretva. Before it was utilized for hydro exploitation via various hydrotechnical interventions and systems with different purposes, Trebišnjica used to be a sinking river, rising and sinking through its course before resurfacing at various places from the Neretva river below the Čapljina to the Adriatic coast, and along the coast from the Neretva Delta to Sutorina.

With a total length of above the ground, and roughly another below the surface, the Trebšnjica river is one of the longest sinking rivers in the world with the total of above and under the ground. In hydrological terms, it represents a sub-basin within the Neretva river basin.