B.Scharte: 180°, B.Zinken: 210°, HSK: 070°, VSK: 210° (Austria '90 survey book pp79-80). Camp is on 144°, +1.5° inclination, but cannot actually be seen from entrance.
The main entrance joins with a secondary, slightly smaller entrance in a daylit chamber on top of a snow plug. Sky can be seen through a third entrance in the ceiling, which is surrounded by undergrowth on the surface.
A hole down the back edge of the snow plug leads to a slither down a partially iced steep (30°) boulder slope, with a low ceiling which soon rises. A large boulder several metres across is jammed across the slope at a few metres further down, below which the boulder slope continues. An inlet to the left just before an ice formation soon becomes too tight. Carrying on, the slope soon gives way to a traverse above a vadose canyon, with a laddered climb (20') after about 25m. It is possible to continue along the top of the rift for a considerable distance (apparently to above Shell Pitch?). From the bottom of the ladder, the passage soon drops down a climb of 2m. Then there is a winding, rifty passageway, named "Magic Mushroom Passage" due to the peculiar mushroom-like formations on the walls. These, together with the white dusty look of the walls in places, give the cave its name. After 100m the rift widens, and a traverse develops above a narrower rift below. The upper level may be followed to above the first rope pitch, but the more usual route is to climb down a rock pile into the lower rift (40cm wide), which is known as the "Yorkshire Ripper", due to the effect of the sharp, narrow rift on oversuits, and the Yorkshire feel of the cave at this point. After 15m, relieved at one point by a small alcove with an irritating spray of water, the narrow rift widens, after a final flourish, to the head of the first rope pitch (6m). Carrying on from the base of the pitch, the tiny rift in the floor deepens, and traversing along leads soon to the head of Shell pitch (19m). Descending gives a fine view of the chamber, the walls of which contain many large bivalve fossils (hence the pitch's name). From this chamber, a short traverse leads to a junction.
Left is an unclimbable aven, whilst to the right is "Piezo de Resistance", described below. The main route is currently down "Q8" pitch which is broken by a ledge after 16m. After a further 9m and a rebelay, a pendulum through a window to one side leads on. Descending further, the shaft stops after 19m and a further rebelay. There are no passable ways on from the bottom ("Strike One"). After the pendulum, a vast army of rebelays lies in wait ("Dot to Dot"), eventually ending in a larger pitch (25m) the bottom of which, again, has no ways on ("Strike Two"). Yet again, a pendulum (at -14m) yields more cave ("Bottom Bypass"). A dubious 11m hang leads to a ledge. At one end of the ledge, ducking under an arch enters a chamber at the bottom of a high shaft ("Lady's Loo"), down which a vast torrent pours in wet weather. A further 9m down from the ledge is a floor. Progress can be made along the top of a slimy keyhole shaped rift ("Tarzan's Folly") which is irritating to pass, especially with tackle. After 20m, a false floor appears and a few metres further on is "The Dark Room", a high chamber with dark, textured walls. A waterfall cascades down from unfathomable heights, and pounds onto a ledge to the back right of the cavern. Climbing down a slimy slope, (which in an ideal world would be lined), the way on is along a rift which exits from the rear of the chamber on the left side. The rift has a couple of false floors in it. The middle level leads to the head of the next pitch "Natural Redundancy" (11m) is reached after about 10m. The rope is belayed to a large chock stone at head level, then to a bolt about two inches from a beautifully rounded thread, hence the name. "Cyclotron" pitch follows immediately, then comes "Quark, Strangeness and Charm", a rift passage with many possible traverse levels. In places there are flowstone bosses, and near the roof, some odd "tippex" stals can be seen. The formations are only notable due to their rarity in the caves of this region.
At the end of QS&C, the passage sweeps round to the left as the floor drops away into "Cloud Chamber". The pitch is broken by two rebelays. The grade 5 survey stops about 20m back from the pitch head. The details of the passage leading to the next pitch are uncertain, although the consensus is that it is around 20-30m long, and fairly straight. The lack of information lead to the name "Amnesia Alleyway". The next pitch is "NDE", an acronym for "Near Death Experience", since a party of cavers was flood-pulsed just below this pitch during the initial exploration. This incident also named "The Delicate Sound of Thunder", another rift passage with a traverse along to a laddered pitch ("Traditional Style"), which is the as far as exploration has got to date.
From the head of "Q8" pitch, an alternative route may be followed. Taking the passage to the right, a traverse develops after 10m. Water sinks into a hole in the floor after a further 10m, and beyond this, is a 9m pitch, followed after 10m or so by a longer pitch with has been descended for about 20m. This point is 60m above the floor of "The Dark Room", and the horizontal separation is only a few metres, so it seems there is a good chance that there is a bypass for the rebelay forest of "Dot to Dot" and the awkward crawl "Tarzan's Folly". Note: The pitches at the end of Piezo were rigged from a couple of somewhat dubious naturals, and could do with being bolted if this is to become the main route.