Water is one of the most important natural resources of east Herzegovina. Trebišnjica possesses a vast unused potential, and it used to be the longest sinking river in Europe (98km). It is precisely in Trebinje where its beauty takes a full form.
Because of its still flow, Trebišnjica is more than suitable for sport activities. It is very clean and clear a has an abundance of fish, so it is very convenient for diving and fishing. It is home to some endemic species, such as ‘gaovica’ (species of ray-finned fish) and famous olm (proteus), which lives in underground river streams. There are also manty popular picnic places along Trebišnjica banks, the most famous being Studenac and Lastva.
Banks of Trebišnjica are intertwined with many bridges, and those standing out with exceptional beauty are Perović (Arslanagić) bridge, Ivo Andrić bridge and Stone bridge.
Trebišnjica streams flow through Gatačko, Cerničko and Fatničko karst fields, where they get lost in underground pits and reappear south of Bileća as Trebišnjica river. Its streams also appear as the source of Ombla – a river in Dubrovnik, and the biggest part of them goes through underground systems to Neretva.