In southwestern Herzegovina is a beautiful valley Popovo Polje . This bit of ancient limestone field is part of the largest karst areas in the world that stretches all over from the Croatia all the way to Slovenia

Near the small town of Ravno and Orthodox Monastery Zavala is the largest cave system discovered in Bosnia and Herzegovina -Vjetrenica cave . Cave channels have a total of six kilometers and a stunning Main channel stretching 2.5 kilometers into the bowels of the earth . Trails intended for visitors are clearly marked and illuminated . Among the many archeological findings, there are the remains of cave bears and leopards , cave drawings whose age is estimated to be 10,000 years old .

The cave is also home to numerous small lakes where endemic cave salamander that can only be found in underground water systems live. Vjetrenica is now as a UNESCO protected area in Bosnia and Herzegovina . The cave was recently reopened to the public after extensive research and improving infrastructure

Opening hours are often changed , and it is best to contact a local travel agency before visiting . There are well- marked road signs on the road that goes through Popovo Polje from Stolac to Trebinje and on the road that goes from the Adriatic coast to the town of Ravno.