Clywedog Valley was pivotal to the Industrial Revolution.

The fertile Clywedog floodplains had always provided rich pasture and corn. As the Industrial Revolution drew more people to the area to work in the coal mines, lead mines, limestone quarries, ironworks and smelting works, the demand for food grew. During the eighteenth and nineteenth centuries, the fast- flowing river powered 18 mills along its length as new mills were opened and areas of woodland were cleared for growing crops. At least five corn mills opened to meet the demand for food, the best known being Nant Mill. The village of Bersham (Y Berse) at one time boasted three paper mills; Bersham Mill overlooked by Bunker’s Hill, the Esclusham Mill and the Esless Mill situated near Esless Hall in Esclusham. Possibly the most famous mill is the Esclusham Mill, better known as the Turkey Mill which dates back to the Restoration. The Mill specialised in the production of extra superfine hand-made bank notes and cheque papers of all descriptions. Indeed the mill became famous for the production of bank note paper and was contractor to the Government Stationery Office. Other customers included colonial governments and banks as well as other paper firms. There is very little visible evidence of the mills today other than Laurel Grove, the mill owner’s house in Y Ddol which is directly opposite the Turkey Mill.

Ordnance Survey map of Bersham, 2nd edition, 1900 showing Bersham at junction of Bersham road (B5099) and Berse Road (B4095), Bersham Bridge over the River Clywedog, Bunkers Hill, Turkey Mills, Laurel Grove, mill race, weirs, Esless Hall and Esless paper-mill.