Sian visits the old quarrying communities of Blaenau Ffestiniog and Bethesda.
Just as the South Wales Valleys were built on coal, these communities were built on slate.
Sian meets the quarrymen, now retired, who were working up to the 1960s in conditions little different from those their Victorian forebears had to endure.
Light was provided by a candle stuck in a piece of clay and silicosis from slate dust was a constant hazard of the job.
However, there were positive aspects to life in the quarries: we discover the culture of the caban, the quarrymen's canteen, where discussion and debate were raised to an art form.