Popovo Polje

Popovo Polje is a large karst polje in the southernmost part of Bosnia and Herzegovina, near the Adriatic coast and the town of Trebinje. The elongated plain runs about 65 kilometers from east-southeast to west-northwest, varies from under a kilometer to about seven kilometers wide, and its floor sits roughly 270 to 300 meters above sea level within limestone walls up to 700 meters deep. The Trebisnjica River crosses the polje and is considered the largest sinking river in the world, disappearing into the karst rather than flowing to the sea on the surface. The polje's western end holds the Vjetrenica cave system, known for a rich community of endemic cave animals, and the whole formation has been proposed for UNESCO World Heritage recognition. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/