The Borehole is close to Pool Sink; it joins the main Ease Gill system at the same place as Pool Sink; and like Pool Sink has been given a grading of III. There, however, the similarities end. Once the first few metres are wriggled through, Pool Sink is a pleasant amble along high meandering passages, linked by a few easy pitches. The Borehole, however, although without any real difficulties, is a sustained trip full of minor obstacles which never really relent. One can never walk upright for more than a few metres; annoyingly deep pools abound; and navigation is not quite as straightforward as one would like. It is, however, a superb caving trip, and the purpose of this guide is to allow people to enjoy it as a pull-through without having to worry too much about the navigation issues.
Although there are not normally any major streams in The Borehole, do note that it floods to the roof in many places when the beck is running, so choose your day carefully.
The entrance is in the true left bank of Ease Gill in the small gorge below Pool Sink. It drops down a couple of climbs, to where it intercepts a passage. Make sure that you select the downstream outlet, which develops into a hands and knees canal. The way to the pitch is reasonably obvious, except that at one point the stream disappears into a gravel choke to the left, and the way on is through a low bedding straight ahead for five metres before negotiating a hole through some boulders on the right to rejoin the stream in a chamber.
The pitch is a superbly sculpted shaft, belayed from a couple of rather poorly positioned non-CNCC P-bolts. The scaffold pole above is best not used, as the rope can creep down and become wedged. Two 20 metres ropes are ample. The landing is on a ledge about three metres above a pool, and it is best to pull the ropes down from here and free-climb down the rest of the way.
The high rift passage at the bottom degenerates into a tube which eventually pops out into a larger passage. Upstream is choked, but downstream emerges into the large Mottershead's Chamber. From here turn right, and head for a gap between the boulders and the roof at the end. On the other side of the gap a short descent drops into a fragment of a superb swirling canyon (dropping down the hole in the floor in Mottershead's reaches the same point). Three ways lead on from here: a hole to the left; a slightly muddy climb up straight on; and a climb up into a roof passage on the right. Ascend into the middle passage which rises to a junction. Turn left for a few metres to where it is possible to lower yourself over a muddy boulder into a large chamber below. Continuing down the slope between enormous boulders leads into a somewhat friendlier chamber with a depression on the left, and a passage guarded by some stalagmites straight on. The latter is not en route, but is a superb passage and worthy of a ten minute detour.
The way on is to enter the depression and at the bottom of the first small drop look behind you where you will see a gap between some boulders. Lower yourself into this and enter a bedding plane containing the stream. Follow this bedding until it is almost blocked by a large boulder. Wriggle over this to the left, and keep straight on in a rift which soon morphs into a separate passage. This is the Eccles Bypass. There are a couple of junctions, but keeping straight on in the larger passage eventually goes through a slightly more constricted section to a crawl over some loose cobbles into the bottom of a well. Climb out of this and you will emerge near the terminal Green n Smelly choke, with the climb up into Spiral Staircase Passage on the left (a route to the Wretched Rabbit entrance rifts), and a drop down towards the bottom of Pool Sink on the right.
This is a fun trip which traverses a wide variety of obstacles. It is, however, quite strenuous and probably not suitable for larger groups.