The Three Galleries

Why this quarry

The slate here was worked from the 1840s until just after the First World War, and it was never a good quarry. The beds ran at an awkward angle, the rock was friable, and the finished slates split short. What the workings did leave is a set of three horizontal galleries cut into the hillside, connected by a narrow tramway ledge that is now the smoothest walking in the whole valley.

That tramway is your route. Everything in this multi follows it, and once you are on the ledge you can walk the whole thing without scrambling — which is why the terrain sits at four rather than five despite the height.

Stage one: the counting wall

From the published coordinate, face uphill. Above you is a drystone wall of the local slate, laid in courses that get progressively thinner toward the top — a builder's trick to save material on a wall that only ever needed to hold sheep. Count the courses from the ground to the coping stones.

• Odd counts are common; if you get an even number, count again from the base, not from the top.
• The number you want is the count modulo five. That gives you the bearing offset in tens of degrees to apply to the gallery entrance.
• The wall has been rebuilt in places. Work from the section immediately below the gate, which is original.

Stage two and three: along the gallery

The bearing takes you to the mouth of the lowest gallery. Walk in as far as daylight allows, then use a torch. The gallery is about 1.6 metres high at the entrance and drops to under a metre within twenty metres, so most people end up crouching. Stage two is a film canister cable-tied to the roof prop, right-hand side, roughly twelve metres in.

Stage three is out on the tip, not in the gallery. The spoil heap below the second gallery is unstable — it is loose slate, it moves after heavy rain, and the edge is undercut. Approach from the tramway ledge and not from below, stay at least three metres back from the crest, and read the container without stepping onto the slope itself.

Stage four: the find

The final is a micro in the second gallery, described in the hint as wedged behind a slab the size of a door. That is literal. The slab leans against the wall about forty metres in, and the container sits in the gap behind its lower corner.

Bring a pen. The container holds a rolled logbook and nothing else — no pencil, no swaps, and no room for anything.

Terrain and footing

• Slate dust is abrasive and slippery when wet. The tramway ledge has a fine layer of it.
• The galleries are not maintained structures. Do not lean on the roof props or the roof itself.
• This is an active sheep grazing area. Close every gate.

After the find

The Rhyd Ddu path continues up to Bwlch Main and on to the summit, but the far better finish is downhill through Beddgelert Forest, where the waymarked trails are graded and the views back to the quarries show you exactly where you have been.