Bileca Lake is an artificial lake located in the municipality of Bileca, in the entity of Republika Srpska, Bosnia and Herzegovina, its length forming part of the Montenegrin border thus a small part being within Montenegro. The manmade lake was created by building the Grancarevo Dam an arch dam across the Trebi_njica River, which was built in 1968. It lies in the upper and central part of Trebsinjica valley, 17 km from Trebinje town and is one of the largest lakes in Bosnia and Herzegovina.