 Traditionally , agriculture was the mainstay of the economy of this part of Wales , but with the Industrial Revolution , the North Wales Coalfield was developed and parts of eastern Clwyd around the Dee estuary and Wrexham became industrialised . The advent of the railway running from Chester along the North Wales coast in the mid @-@ nineteenth century made it easy for urban dwellers from Lancashire and Cheshire to visit the seaside towns of North Wales , and nowadays , tourism is the main source of income in Clwyd . 
