The "unroofed cave" near the bunker (Laški Ravnik)
Milan Geršl, Uroš Stepišnik , Simona Šušteršič - (28/2,1999)
Situated in the Laški Ravnik, about 4 km east of Planinsko polje (Slovenia), this unroofed cave is the longest of many found in the area. More than 200m of denuded passage has been traced at the surface. The cave's general trend is north - south. Three main "passages" making up the unroofed cave have been recognised, and each has been transformed in its own way. Disintegration of parts of the former cave roof is apparent, forming "false solution dolines", between which the ceiling is partly preserved, either in-situ or as isolated blocks lying on cave sediment. In the down-dip direction, passage sides have disintegrated almost completely, and detached blocks have slid down into washed-out portions of the former cave passages. All three passages developed along bedding planes, but in different directions, such that two of them now "emerge" above the surface whereas the third plunges down and is completely choked by loam. The unroofed cave passes southwards into a "normal" underground route, where a barely accessible, low and wide passage is accompanied by two "vertical" shafts, which are presumed to be former phreatic jumps. This part of the system is not considered in this paper.