Ariel Cave
AKA Blacknor Hole
Overview
Ariel Cave (more commonly referred to as Blacknor Hole) is undoubtedly the finest cave on the island. The round trip coupled with an excursion or two into the side rifts or the continuation of Ariel tunnel as far as Brownsea island, provides a good 2 to 3 of hours of entertainment. When the excitement of the entry and exit to and from the cave is also considered, an excellent day out can be had. On the whole the cave is relatively clean, in good condition and contains some excellent formations (if you can find them).
In addition a number of through trips are possible making use of the more recent connections which have been forged into neighbouring caves (Sandy Hole, Hopeless Hole and Persil Rift). Details including trip descriptions for these can be found on the West Cliff Trips page.
Cave length: 875 m (Excluding linked caves)
Ariel Main Entrance: SY 67910 71665 (50.54387, -2.45424)
Queens Entrance: SY 67900 71632 (50.54357, -2.45437)
Location
The entrance is approx. 10 m down a 30 m sheer cliff which is at the top of a 50 m, steep scree slope. Consequently, getting to the entrance isn't straight forward and provides half the fun of the trip...
Park in the climbers car park at West Cliff and follow the path to the cliff top. Turn right and follow the coast path North towards Blacknor Fort. The path significantly narrows as it passes behind Blacknor Fort. As it begins to widen you will see an obvious take off point on the cliff edge adorned with 3 resin stainless steel anchors from which an abseil can be rigged. If you begin to drop down into an old quarry working you've gone too far. Unfortunately the entrance is more or less invisible from above.
To get to the underside of the entrance continue along the path Northwards, dropping down into the above mentioned old quarry workings. Directly opposite an obvious track to the right there is a steep climbers path leading over the cliff edge. Follow this back South along the underside of the cliff until you get to a point where there is an obvious large block segregated from the main cliff on your left and an elder bush on your right (its the only significant bush along here). The entrance is directly above this point. As with the abseil take off the entrance is more or less invisible from here! Be warned, the climbers path is a little sketchy in places and certainly requires a degree of care. It becomes even more interesting in the wet.
Entry / Exit
Entry is possible from both above and below. The first person must either abseil from the take off above or lead climb from below. If abseiling, the take off is far from the friendliest. It's a rounded edge which quickly becomes an overhang. The entrance at -10 m becomes obvious once part way down the cliff and requires an interesting move to enter as a result of the overhang. A 45 m rope is recommended as this allows plenty to reach the bottom of the cliff should all not go to plan. This is also sufficient to rig a pull through upon exiting (see below). If the first person climbs from below they'll need to be competent at lead climbing - the route is Drag Racing Underground at 6c+ (details in Dorset Rockfax) with the entrance being found at 20 m above the path. Clip-sticking your way up is also possible although the bolts are not exactly close together on this route.
As for the rest of the group they can either follow down the abseil or the rope can be re-rigged for SRT from two bolts to form a Y-hang (up and to the left when looking out of the entrance) to allow them to ascend from below. There is a third bolt 1 m into the cave on the right hand side to provide a traverse line. This is often considered the more 'friendly' option. If the entire party enters the cave from above, please note the rope will not pull through the bolts and hence taking a second rope for exit may prove the most efficient.
Once finished in the cave, the easiest way to exit is to abseil from the the pair of bolts mentioned above to the climbers path below. The last person needs to rig a pull through from the two bolts so that the rope can be retrieved. 45 m is sufficient to allow for this. If using a single rope, the first out may need to return to the top of the cliff and release it from the abseil point to facilitate this. Note that communication is tricky, particularly in anything more than light winds.
Do not rely on a rope rigged from above the cave entrance if it has not inspected after your trip. Remember it is alongside the footpath and very liable to being fiddled with. Also, ensure any rope used from above is tied into the entrance. If the wind blows it is not possible to reach the rope from within the cave if only attached at the abseil point. The end is also likely to be flailing around along the cliff!
Allow an hour in addition to the trip times given to deal with the entrance.
A second entrance to the cave, Queens Entrance, can be found approx. 40 m further south under a prominent overhang. This entrance is also hard to spot from below, impossible to see from above and is not equipped with suitable hangers to allow entry / exit. The nearest bolted climbing route to this entrance is 'Wynona's Big Brown Beaver'. Skilled climbers may be able to enter the cave by lead climbing this route.
Kit
45 m rope (less faffing with two 45 m ropes), 6 carabiners and a sling to tackle the entrance (+ personal SRT / abseil gear).
10 m handline may prove useful for less experienced (Grand Canyon crossing, climb out of C&A Rift).
15 m hand or life line to descend into Tangerine rift (some may prefer a 10 m ladder).
6m ladder and 15 m lifeline for Mustafa (AKA Next to Go Rift).
Sketch of the cave:
I have provided two sketches of the cave. The first suitable for the round trip and the second showing all the West Cliff Caves useful for the longer through trips.