The River Trebišnjica is a significant river located in Bosnia and Herzegovina. It is known for its unique karst features and is one of the longest underground rivers in the world. The river flows through the Trebinje region and is a vital water source for the surrounding areas. The Trebišnjica is approximately 100 kilometers long and has several tributaries. It is famous for its clear blue waters and picturesque landscapes, attracting visitors and nature enthusiasts. The river also plays an essential role in local agriculture and hydroelectric power generation.