In order to establish modern research on cave faunas from Slovenia, a co-operation for several years between the University of Vienna, the University of Ljubljana and the Austrian Academy of Sciences was established in 1996. The idea behind was to complete the results of former excavations with new methodological approaches. The focus lay especially on determining the chronological age of fossil finds and artefacts by radiocarbon dating and on studying the fauna remains in the light of the newest palaeobiological research standards. In Krizna jama (Kreuzberghohle) we followed the example set by the successful additional excavations in Potocka zijalka and Ajdovska jama. It is one of the most interesting caves in the classical karst area. Not only is it possible to admire magnificent sinter structures but also to follow eight kilometres along a unique subterranean stream in an inflatable dinghy. Krina jama is less well known as cave bear site even though an excavation team from the Natural History Museum in Vienna carried out palaeontological excavations already 125 years ago. Additional excavations in 2000 and 2001 recovered rich fossil layers with many well preserved cave bears remains that allowed for clarifying the following scientific problems: the systematic position of the cave bear remains, the time period in which the site has been used for hibernation, as well as certain peculiarities in their behaviour compared to other cave bear faunas. Additional articles concerning the history of excavation, the geology of the surrounding, the extremely interesting course of the subterranean regimes, the speleothems and sediments as well as regarding the modern cave fauna and troglobites complete the monograph. Printed with support of the Austrian Science Fund FWF.