Adit and ?shaft. Greenly 1919; M J. 1835; OS

CaMoA has Llaneuddog Mine/Caeronneg Mine and Brynfyches Mine at roughly similar locations.
Porth yr Aber is also close, but CaMoA attributes that to possibly being a drainage adit for Rhosmynach

The Mining Journal of 1853 contains [p 201] a flattering ‘puff’’.

“On sale, Mining Concerns at Caeronneg, parish of Llancilian [sic], Anglesey. Containing about 40 acres of valuable land. Is situated about 1 mile from Parys Mts, about 2 miles from the smelting house, Amlwch and half a mile [more like one mile!] from the sea shore. Perceptible are three or four veins of copper running through the land into the mountain. A shaft has been commenced and sunk about 9 yards, where the veins are calculated to join. Another is now sinking on one of the veins, a short distance from the former shaft for the purpose of providing same. They have raised in a few days 2 tons of copper… it is improving as it
gets deeper”.

[follows details of royalties ].

for Porth Helygen, Greenly 845 states:

“A level was once driven for copper in the Gneisses a little to the south of this
cove (p 328), and chalcopyrite was obtained. Lead is also reported to have been worked near
Dulas.”