POSTOJNA

German Adelsberg, Italian Postumia, town in western Slovenia, on the Pivka River northeast of Trieste. Long a local market centre, it is on the rail line and road from Trieste to Ljubljana. Its prime importance is as a tourist centre for its Postojna Cave, an internationally famous cave system considered by experts to be the best example in Europe of karst phenomena-heavily and irregularly eroded limestone structures and underground streams. A mile from the town is the entrance to the vast cave system, which is divided into several branches. The Pivka River enters the Postojna cavern 60 feet (18 m) below its mouth, runs underground, and reappears as a spring in the Planina Plain. The cavern has 9.1 miles (14.6 km) of corridors and grottoes containing spectacular stalactite and stalagmite formations. In parts of the system is found a remarkable eyeless, colourless, snakelike subterranean amphibian, Proteus anguinus, growing to 1 foot (30 cm) in length, which lives on snails and worms and has both lungs and gills. An upper gallery was the scene of a famous exploit during World War II, in which Partisans exploded a German fuel dump; the smoke-blackened walls are still visible. Northwest of Postojna is the medieval Predjamski Grad, a castle built into another cave, which houses an extensive archaeological collection. Pop. (1981) 7,681.