A combination of 2 earlier workings with tunnels and other remains.**

Divided by a causeway constructed to provide later access to the Ffridd incline. A large, ruinous mill and several associated buildings survive. At the lower level, a substantial working area includes ruined buildings, a tunnel from the pit, and several inclines including the mill-powered up-haulage. Vestiges of a barracks are present, along with extensive rubbish runs and remnants of tunnels and dressing sheds. An interesting building beside the Ffridd incline, featuring a heavy slab roof and a fine fireplace, may have served as a Caban.

Formed from two very old workings. The eastern section (Ddol) was abandoned early, while the western section was further developed with a tunnel connecting to the mill area. Before the construction of the Ffridd incline, material from the western site was transported to Caernarfon. A short self-acting incline initially connected the site to the original head of the Ffridd incline, later replaced by a tunnel. Following the extension of the Ffridd incline, access was routed via the head of the lower pitch of the extension. Around 1890, a mill was reached by converting a gravity incline into an up-haulage powered by the mill engine. Output was modest, unlikely exceeding 1,000 tons per year, recorded at 631 tons with 26 men in 1882. The quarry closed during World War I.