Mongo Gill Hole is an unjustly neglected cave which sees a few visits a year from long-standing friends, but tends to be ignored by the rest of the caving fraternity. This is unfortunate, as not only does it have a wonderfully evocative name, it also offer a fine afternoon's entertainment with a wide variety of fascinating passages and a host of excellent formations. It does have a reputation for being difficult to find your way through, with one account claiming that it took 45 minutes to find the way on from the bottom of the entrance shaft, but this is one of only two or three places on the main route where it is possible to flounder.
Mongo Gill is the upstream end of the Stump Cross Caverns system, and has three entrances. South Entrance which requires no tackle, but is normally blocked; the nearby North Shaft which is located close to the stream sink; and Shockle Shaft which lies midway between North Shaft and Stump Cross. The classic trip is an exchange between Shockle Shaft and North Shaft, but two factors militate against this as a trip of preference. Firstly, there is only 40 minutes of caving between the two, and secondly, although Shockle Shaft is a pleasant mine shaft, it is immediately succeeded by a gungy section of passage which will inevitable result in a filthy rope.
The following trip enters the system through North Shaft, visits the main features of the cave including getting to within a few metres of the base of Shockle Shaft, and then returns the same way. It should take a leisurely four hours, and knee pads are recommended.
North Shaft can be descended using SRT (rigging guide), and has a couple of permanent bolts at the top. A cunning deviaton from a piece of cord threaded through the concrete base keeps the rope away from the manhole entrance and the walls. The initial landing is on a large ledge. The last few metres can be free-climbed, but the rope can be re-belayed from a sling threaded through a hidden eye-hole to assist. Once down, SRT gear can be discarded.
The way on can be difficult to find. Follow the near wall to the north (facing the rope, to the right). This leads to a drop into a descending passage. Follow this straight on through a small chamber into an ascending passage for a few metres to where it looks as if it is going to choke. Keep going, however, and an ascent up sloping bedrock will be found at the end on the right. This leads up to a T-junction with low beddings going off to the left and to the right. Go left. It is marked by a wriggle round a couple of boulders. This is Lookstone Level, and you are now on your way.
The route is now obvious for the next 250 metres. Shortly after a chamber with a small shaft on the left, you need to slide past an impressive stalagmitic boss. This marks the start of 150 metres of superbly decorated passage spoilt only by the dullness of the formations. It is the sort of passage which previous generations would have called a "gallery" The height varies, from romping height, to flat-out slaloming through miniature columns.
All good things come to an end, and all too soon you are in a chamber with an obvious rock fall. This is East Hade. Regrettably, the way on is down a hole on the left into a flat-out crawl half-filled with water. Happily, it isn't as bad as it looks, and it doesn't last long. The constricted passage soon widens out, and emerges into a large chamber, J.J. Cavern, with another rock fall. This time, the way on is over the boulders, keeping to the right. The passage at the top descends drops back down, and after 50 metres a large chamber is entered through a bedding and a calcite slope, with a passage ascending on the left. This is Judson Cavern, and our way is to the right past a large fallen stal. We then pass through a section of passage which has had a channel dug through the fill by the miners.
This section finishes where the main passage is obviously choked with boulders and calcite. Close to this is a metre-deep drop under the left hand wall, into a mine level. We need to follow this for the next 50 metres or so - but with great care as there are two or three places where it passes through unstable sections. It is worth climbing out of the level at the first rock fall into a massive well-decorated chamber, New Cavern.
Towards the end, the mine level morphs into a coffin-shaped rift passage and emerges at the top of a slope which leads into a chamber. This is 1792 Cavern, and is characterised by a couple of craters in the floor. Opposite the point of entry is an old calcite floor jutting out of the wall. The way on is a traverse round a mud bank to the left, which climbs into a passage above the calcite floor. This leads almost immediately to a drop, equipped with fixed aid, into Ladder Cavern.
Again there are some craters in the floor, and you need to traverse round these into the continuation of the large passage. Another hole is passed to the left - note this as we shall soon be popping up through it. After another few metres Bell and Pratt's Passage takes off to the right. This is the way on, but first continue for a few metres to where the floor starts to become liquid clay. Shockle Shaft is a few metres further on, but to reach the bottom requires a paddle through the mud to a low passage on the right which rises into the base of the shaft.
Return to Bell and Pratt's passage, and follow the crawl round to a drop, which looks formidable, but is actually quite easy. At the bottom is Vein Cavern. You are now in the active stream series - a place to avoid in wet weather. Vein Cavern has three passages going off - a short mine level, a crawl under the wall upstream, and an obvious passage downstream. The latter is about 150 m long, and is worth visiting. It is on two levels, with the lower level reaching a sump, and the other leading to a clay choke, which once connected with Stump Cross Caverns.
Returning to Vein Cavern, follow the passage upstream through a wide sandy crawl, known as the First Sump. This leads into a large stream passage, which evidently sees some ferocious water flow. In dry weather, the stream passage can be followed for a considerable distance towards the sinks, through some superb stream passage separated by dried out sumps. Before the second sump is reached, however, an iron ladder will be seen ascending into the roof. Climb this into a short section of ascending passage, which pops out through the floor of Ladder Cavern. From here retrace your steps back to North Shaft. The route out is a lot more straightforward to follow than the route in.
There are other passages worth exploring in Mongo Gill, but the above route is not only worth doing in its own right; it also serves to familiarize the first time visitor with the basic features of the system in preparation for further investigations. Have fun!