Pivka jama – outflow sumps of the underground Pivka (Postojna system)
Behind Pivka jama, part of the Postojna cave system, the Pivka river flows on through a chain of outflow sumps towards Planinska jama. Divers first passed the 170 m long, 30 m deep first sump in 1975; in 2015 a sidemount team led by Igor Vrhovec and Sebastjan Gantar passed a fourth sump and surveyed 3.5 km of new river passage, and in 2017 they linked Pivka jama with Magdalena jama naturally through the extended Zvezni siphon (422 m, 17 m deep). Visibility is typically half a metre or less, and a large olm colony lives along the route.
Tiefe: 0–30 m