Blaneau Ffestiniog to Penmachno Via old slate mine railway

Armoredinca

I have heard that there is a dis-used slate mine railway line that runs up out of Blaneau Ffestiniog through a couple of old mines and that it meets up with a track at Penmachno.

Has anyone got info on where the railway line starts out of Blaneau and where abouts it drops into Penmachno forest from the slate quarrys?

Cheers Chris