Modern visitors, people from places like the USA and the Far East, men and women who know little or nothing about Welsh history, heritage and culture, might be excused for thinking that many, if not most, of our valleys were never industrialised at all.
Welsh miners at Tylorstown Pit, Rhondda, 1943
They might have heard stories about hymn singing Welsh miners on their way to and from the pit but where, they might ask, is the evidence?
Such is the extent of modern day de-industrialisation that in many places visitors invariably see only green hills and rugged mountains; the coal mines and iron works, the copper mills and the steel works, that once littered the valley floors might never have existed at all. And yet, as those of us who live in Wales know only too well, nothing could be further from the truth.
And yet it did not begin that way. Until the middle years of the 18th century it is fair to say that industry, where it existed in Wales, was decidedly small scale with a mixed and part-time work force.
Throughout the 17th and 18th centuries, men, women and children would labour in the fields, on the farms, during the summer months and at harvest time.
But when agrarian needs were not so pressing they would move across to the coal mines and iron foundries to earn their daily bread.
The first reference to coal in the country came in 1248 but it was not until many years later, in 1695, that Humphrey Mackworth began to use the fuel to smelt copper in the area around Neath. It was a slow beginning of a process that took years to reach fulfilment.
Two of the driving forces behind the industrialisation of the country were war and a desire for improved social environments. Conflicts such as the costly Napoleonic War demanded new weapons - guns and cannon - while better wages and living conditions in cities like London meant that there was an urgent need for more luxury goods.
From the 1850s onwards, as the Industrial Revolution began to throw up an unprecedented demand for iron, copper and tinplate that people began to realise that Wales might be the answer to difficulties such as supply and demand.
By the middle years of the 1860s the Mona and Parys copper mines on Anglesey had been created and were employing no fewer than a thousand men - and women. The slate mines and quarries of Blaenau Ffestiniog and Llanberis gave employment to thousands more.
When a copper smelting plant was established at Swansea it created a community that soon became known as Copper Kingdom, its sailing ships travelling across the world with cargoes of the precious metal.
When, at the end of the 19th century, investors like John Guest and Richard Crawshay saw that all the materials needed to produce iron - iron ore, limestone, coal and wood - were readily available in Wales, there was a rush to the valleys of south Wales.
By 1820, just five years after the end of the Napoleonic War, under the leadership of men like Crawshay and Francis and Samuel Homfray, the ironworks of Wales were producing nearly half of all Britain's iron exports.
And coal? Until the 1830s Welsh coal had been used principally as household fuel. Then came the steam ships of the Royal Navy and the burgeoning of the new railway system. And coal, its production and delivery, became an industry in its own right rather than being simply an extra, an adjunct to the smelting of iron and copper.
In 1850 the Rhondda Valleys, both Fach and Fawr, boasted fewer than 1000 inhabitants. By 1910 the coal rush - for such it was - had increased the population of the two valleys to over 150,000. People worked long hours in difficult and dangerous conditions.
Wages, although no doubt better than would have been earned on the farms of the rural homelands, were low and many workers were paid in tokens that were only redeemable in the company truck shop - where prices were, of course, very high.
Almost overnight the valleys turned black from smoke and soot and grime. The angular arches of pit winding gear and huge mountains of slag littered the hills. Houses lined the valley sides and the delicate infrastructure of the communities was simply not able to cope.
Poor housing, awful sanitary arrangements, dreadful living conditions - they brought diseases such as cholera, typhoid and typhus. And, of course, it was inevitable that, sooner or later, discontent would be sure to raise its head.
The Merthyr Riots of 1831, which saw the death of more than a dozen rioters and the arrest and subsequent execution of Dic Penderyn, were just the tip of the iceberg. Bands of men, known as Scotch Cattle, were soon roaming the valleys and hillsides, supposedly punishing those who sided with the mine and foundry owners but, in reality, stealing, looting and bullying anyone with whom they did not agree.
The Chartist movement had begun in the 1830s. It was a movement dedicated to social and political reform and its members were committed to achieving fair representation for all working men.
Their six point charter of 1838 demanded, amongst other things, the vote for all men over the age of 21, a secret ballot and payment for all MPs. In Wales, with the appalling conditions of the industrial areas clear for all to see, the Chartists were well supported.
On 2 November 1839 Welsh Chartists planned a march to Newport. Men came from all the industrial areas of south east Wales and at the town's Westgate Hotel, with feelings running high on both sides, there was a full-scale clash between the marchers and soldiers. Twenty men were killed and the Chartist leaders - John Frost, Zephaniah Williams and William Jones - were arrested and later transported.
Welsh opposition to the mine owners and the drive to improve conditions in the mines, factories, steel and iron works of the country did not end with the failure of Chartism. Men and women continued to fight for their rights but, despite terrible conditions, it was not until the nationalisation of most of Britain's industries in the years directly after the World War Two that working conditions really improved.
As the 20th century drew to a close it was clear that the industrial valleys of Wales were also nearing the end of their working life. Coal seams were petering out, cheaper fuel was available from abroad and the iron and steel industries were but a shadow of their former selves.
Visitors to the now green-again valleys might applaud the process but it is difficult to know if those who spent their lives underground or working in the blast furnaces would agree or not.