HRS 5551 Cwmystadllyn and Gorseddau slate workings 2008
"Quarry developed by Bavarian mining engineer Henry Tobias Tschudy von Ulster in a gallery format. (1850s) Had 2 feet gauge tramway to Porthmadog via Ynyspandy slate works" Source A guide to the IA of N Wales Gwyn and Williams AIA 1996