VIVIAN SLATE QUARRY
RATGOED SLATE QUARRIES
GORSEDDAU SLATE QUARRY
ABERLLEFENNI SLATE QUARRY
MOEL FFERNA, SLATE MINE
CHWAREL YR EIFL; CHWAREL TREFOR
BERWYN SLATE QUARRY AND FIELD SYSTEM
MAENOFFEREN;MAEN-OFFEREN;MAEN Y FFEREM;MAEN...
DINORWIC SLATE QUARRY