Claim: Wales has a large region rich in coal deposits.
Evidence: At the dawn of the Industrial Revolution , development of the mining and metallurgical industries transformed the country from an agricultural society into an industrial nation ; the South Wales Coalfield 's exploitation caused a rapid expansion of Wales ' population.
The South Wales Coalfield -LRB- Welsh : Maes glo De Cymru -RRB- is a large region of south Wales that is rich in coal deposits , especially the South Wales Valleys.