Sub-horizontal passages lead through steeply-hading rifts from this entrance. A lower route was originally explored by a German group before CUCC's first visit, and remains poorly documented and not fully explored. The higher route, explored by CUCC, leads past connections to 142, another CUCC find. Passages trend downhill to reach the Big Pitch of 100m vertical.
Lärchenhöhle connects at the bottom of the Big Pitch, and a streamway leads down. A roof passage connects to CUCC's 144, and another leads on to smaller pitches to the Big Rift, dropping steeply down several pitches to reach Junction Chamber with connections to Schnellzughöhle (115).
The route to 115 also leads to Pete's Purgatory, 800m of awful streamway to the Confluence, much more easily reached by large fossil passages starting with Dartford Tunnel from Junction Chamber. The Confluence is around half the depth of the system, and marks a transition to a single linear streamway leading to great depth, a feature currently unique in the known caves of the area.
The streamway is interrupted by a bypassable sump and several, mainly short, pitches, before a low-airspace canal appears to mark the end. However, a low duck can be passed to reach a deep and very wet shaft Orgasm Chasm which drops to the final muddy passage and short pitch to a dismal and deep rift sump.
The sump is 898m below the 41a entrance, and is at just about the same level as Altausseer See, in whose underwater risings the Stellerweg water is presumed to emerge. The scope for greater depth here seems minimal, but connections to various higher entrances have increased this to c971m, with perhaps a little more potential still to realise (optimistically up to 1058m).
In 2018 Robert Seebacher told us that recent diving had found a deeper funnel-shaped depression in the lake - with rocks at the bottom - where most of the resugence seemed to come from. It had been found because there had been an ice-free area in the lake during the preceding winter. So the story about small resurgences over an area seems to have missed the main outflow.