Popovo polje is one of the most famous polje (karstic plains) in Bosnia and Herzegovina and the world, for its karstic phenomenons and features, and particularly the Trebišnjica river, which flows through the polje as the largest sinking river (also losing stream, or influent stream) in the world, as well as the Vjetrenica cave system, located to the west/south-western parts of the valley.
At the end of Ottoman rule in Herzegovina, the Muslibegović family had properties in Popovo polje.
Located in Popovo Polje in Ravno municipality, village Zavala with its old architecture and stone masonry, together with Vjetrenica cave, constitute the natural and architectural ensemble which is in the process of being protected as National Monument of Bosnia and Herzegovina, and it is already placed on UNESCO Tentative List.
[3] The cave garnered worldwide fame in geological, biological and environmental communities for its imperiled and uncertain future, caused by unprofessional management lacking any expertise, and uncertain status at state and especially local level.
Despite setbacks, the government of Bosnia and Herzegovina, although creepingly slowly, nominated Vjeternica (with village Zavala) to UNESCO Tentative List clearly expressing intention to protect the cave and its biodiversity and eventually inscribe it with UNESCO.