Magnetometer Pot has a triple personality. At the far end a variety of passages offers pain and purgatory for the masochistic, and the near end offers muddy tubes and squalid digs for the optimistic. Fortunately, a trip just to Caton Hall, where the pain and agony starts, is a superb trip, spoiled only by the fact that navigation through the entrance series is not straightforward. This guide describes the route through to Caton Hall, in particularly the entrance series, and points out one of two features that shouldn't be missed. It takes a small party which knows the way well under three hours. Those who wish to explore beyond Caton Hall should refer to Mike Cooper's 'Not for the Faint-Hearted'.
A considerable part of the system floods catastrophically, so it should only entered during a reasonable dry spell.
Permission for descent should be obtained from the friendly farmer at Neals Ing (SD 8411 6906), who also allows a couple of cars to be left in the yard under the watchful eyes of a collie for a pound apiece. The entrance (see map) is in Fornah Gill a kilometre or so upstream of the farm (SD 8495 6971), and can't be missed - a couple of large concrete rings protrude incongruously from the ground. The entrance shaft is most easily descended using a 10 m ladder.
Once down the ladder follow the obvious passage down a few small climbs and through a couple of small chambers. Ten metres past where hands and knees crawling is required a smooth passage through which a fixed rope is visible goes off to the left. Follow this rope down a two metre drop and then down a further 5 metre drop to the lip of Well Pitch. This can be stepped over, still following the rope, into a tube which start with a couple of awkward bends. After a few metres the passage becomes more rifty, and the way on is through another smooth tube which takes off to the right a little above the floor. This leads to a junction with a larger passage with a thin fissure in the floor in which a rope is belayed. The rope disappears to the left, and our way goes off to the right into Wet Crawl. The entrance series is now behind us, and there are no further navigation problems to Caton Hall.
Wet Crawl is about 70 metres long, and lives up to its name. It is followed by the equally appropriately named Dry Crawl which is about 100 metres long and ends at Styx Junction where the character of the cave totally changes. To the left is Styx Slope which leads down for some 20 metres or so to a sump which, judging from the amount of deposited sand and gravel, floods ferociously upwards. It is an impressive section of passage and well worth the ten minute detour.
Straight on from the junction is the Styx itself, a hundred or metres or so of waist-deep canal. This finishes in Easy Street, where the walls and floor suddenly become fretted and sharp, with deeply-milled holes in the floor, and adorned with some fine formations. After a further 150 metres or so Holes Junction is reached, where some interesting caving may be had down the first hole, in a passage leading to a deep sump pool.
The way on is past Holes Junction and then veering to the right. This passes underneath a clean-washed aven, and soon afterwards a narrowing in the floor encourages traversing. Note a passage entering a couple of metres above the floor from the left - this is an oxbow, and is worth following on the way out. A narrow rift appears in the floor, and it is necessary to traverse along faulted blocks to a stance overlooking Milestone Chamber. The climb down is easier than it looks. The next 70 metres or so is predominantly easy traversing, leading to the top of a rift overlooking Caton Hall. Unless one is intending to explore the couple of kilometres or so of passages below Caton Hall, it is hardly worth taking the tackle to descend it.
The way back through the entrance series is straightforward. When the end of Wet Crawl is reached look for the thin fissure in the floor where a rope is belayed. Turn left here into the tubes, and keep turning left until the fixed rope above Well Pitch is encountered. The entrance pitch is just ten minutes away.
This is an excellent trip, with some great caving and superb passages, and deserves to be appreciated by more people. It is also an excellent introduction to the cave for those who wish to explore it further.