|Remains||Tip (visible from track) surrounded by dense undergrowth|
Trial [Holmes 1999: 49].
Holmes  reports anecdotal evidence that Haydn Jones, the Bryneglwys slate quarry lessee 1911–1946, drove the adit in the hope of finding manganese. When work in the quarry was slack, a couple of men would be sent there to extract some material but Homes does not believe any useful manganese was ever found.
Both this trial and the one at Caerffynnon appear (from their spoil) to target horizons close to the Nod Glas / Broad Vein contact. (These horizons are exposed in the Bryneglwys slate quarry Long Tunnel where Fe - Mn stalactites occur but no ore.) [James 2003]
The tip shows a quantity of very lustrous black mineralisation, possibly highly metamorphosed slate. [Roe & Weston 2004]