Cave in Predolac

The most important speleological object in the area of the city of Metković and one of the most important in the whole of Dalmatia is the Cave in Predolac . It is located at the foot of the saddle between the hills of Predolac and Šibanica, today almost in the very center of the city. It was formed in limestone deposits, and is rich in cinder and cave decorations, and it contains an underground lake that is divided by a ridge into two parts with a maximum depth of up to 10 meters, as well as a system of channels and another smaller lake that marks the end of the Cave. The cave is also a habitat for numerous animal species, some of which are extremely rare, such as the Dinaric cave pipefish, cave shrimp, cave crustaceans, river sponge, shrimp, wrasse, freshwater midge, eel, goby and others. However, the most famous inhabitant of the Cave, for which it is protected, is the "living fossil" Congeria kusceri , the only Šiplje bivalve in the world and an endemic of the Dinaric Mountains that originates from the Tertiary period, surviving by going underground when its relatives became extinct 5 million years ago. It is up to 20 mm in size and, since it spends its entire life underground, has no pigment. It is usually attached to the rock of groundwater, individually or in groups. Since the Cave in Predolec is located in the yard of the Vuica family, the family has arranged the Congeria Educational Center right next to the entrance , which presents the Cave and its most famous inhabitant , Congeria kusceri .