Welsh slate quarries

As a Welsh gifts seller that offers a range of slate products, we decided to embark upon a quest to learn more about Welsh slate quarries and their history. Initially slate was extracted for roofing tiles and for marking graves. Wales was a very important exporter of slate to locations all across the globe. Welsh slate has become less sought after though due to cost primarily. Nevertheless, some quarries still operate on a small scale and slate products can be found in households across Wales in the kitchen, garden and as home decoration. Not to mention the slate that has been skilfully used in building construction, such as the Millennium centre and the National Assembly building in Cardiff to accentuate Welsh identity.

Llechwedd Slate Mines

Location: Blaenau Ffestiniog, North Wales

Slate mining began at Llechwedd in 1836 and was pioneered by J.W. Greaves. This mine is renowned for it’s high quality blue-grey slate.

llechwedd slate mine

In 1846 the important opening of a new railway was announced, linking Blaenau with the sea at Porthmadog. It was the first railway to use narrow gauge steam locomotives over a significant distance. A few years later an incline (cable railway) was built connecting the quarry to the new railway line. Production of slate increased considerably during the 1850s and 1860s where it was exported to foreign markets via sailing ships.

In 1890 electrical power was introduced at the quarry via hydro-electricity. In the 1960s the demand for slate began to decline and the quarry turned its attention to trying to generate income in other ways. In 1972 it opened the Llechwedd Slate Caverns tourist attraction, which allowed visitors to learn about the history of slate production and go on a railway journey deep into the mines at the quarry.

Braich Goch slate mine

Location: on the A487 road between Machynlleth and Dolgellau in Mid West Wales

Slate mining at Braich Goch began at the turn of the nineteenth century. After several failed attempts of setting up a sustainable business some much needed infrastructure was built – the Corris Railway of 1859.

At the mine’s peak, in the 1880s it employed three to four hundred people and was bigger than any other Wales quarry south of its location.

Braich Goch quarry
Braich Goch quarry

The mine was closed in 1970 due to fall in demand. Part of the mine is still used for tourist attractions today: the King Arthur’s Labyrinth Tourist Attraction and the Corris Mine Explorers. Corris craft centre is located nearby too with several charming little craft shops.

Oakeley Quarry

Location: Blaenau Ffestiniog

Blaenau Ffestiniog is known as the “The Town That Roofed the World”. Here is mined some of the finest roofing slate in the world. The Oakeley quarry become the largest underground slate mine in the world housing 50 miles of rail track. It was the largest of the several quarries at Blaenau Ffestiniog.

At over 450 million years old the quarries Ordovician slate is particularly strong and durable. The quarry was set up by Methusalem Jones, a publican, in 1765 on the Diffwyd sheepwalk.

In 1825 Samuel Holland had developed the quarry to such an extent, that he received an offer of £28,000 (a few million today) from no other than Nathan Rothschild. Rothschild formed the Welsh slate company and Holland could do nothing but walk away as a very wealthy man.

It was during World War II that a Blaenau Ffestiniog slate quarry was put to an intriguing use. Lorries disguised with chocolate brand slogans on the side made their way to the Manod Quarry. The contents were not chocolate though – they were art masterpieces by the likes of Rembrandt, Da Vinci, Michaelangelo etc. Churchill had instructed the artworks to be moved secretly to the mines of North Wales for protection from the bombing in London. It was a huge operation and the paintings had to be protected in the mines by heavy security doors alongside suitable ventilation and heating.

The quarry closed in 1969 due to the fall in demand for slate. A tourist attraction opened in 1978 called Gloddfa Ganol. The attraction boasted several narrow gauge locomotives, a working mill and access to part of the underground mine by visitors. The tourist side of the business closed when it was sold off to the construction company McAlpine in 1998. McAlpines worked the quarry until it was forced to close in 2010 due to the risk of the mine collapsing.

Gilfach slate quarry

Location: near the small village of Llangolman in South West Wales

The slate mined at this quarry has a unique characteristic. It has a green colour and a grainy texture. It is different to other Welsh slate as it has been formed from organic ash. This band of slate runs along the Taf valley.

The slate is known to have been exploited as early as 1860. In fact there are some claims that the slate was extracted as early as the sixteenth century at Gilfach.

Some have claimed that Gilfach slate was used for the roofing tiles of the Houses of Parliament when it was rebuilt in the 1830s. As well as roofing tiles the slate was used for protecting exposed walls.

Though many of the quarries closed in the early part of the twentieth century, due to cheaper alternatives, Gilfach Quarry still operated up until 1987. There is a small quarry still running at Gilfach, but nothing of the scale of when it was fully operational.

Penrhyn Quarry

Location: near Bethesda in North Wales

At the end of the nineteenth century, Penrhyn quarry was the biggest slate quarry in the world, and continues to be the UK’s largest. One of the first railway lines built in 1798 transported slate to Penrhyn harbour to be exported across the globe.

Penrhyn slate quarry
Penrhyn slate quarry

The Penrhyn family, owners of the mine, built a grand castle near Bangor. Their quarrymen though often worked in dangerous conditions, using explosives to break rock, and for very little pay even having to buy their own tools. Not to mention the problem of breathing in dust which led to many workers to suffer with silicosis.

George Pennant (2nd baron of Penrhyn) refused to allow any trade unions. Consequently a strike broke out that was to be the longest strike in British industrial history. In the latter part of 1900, Pennant ordered a lockout which lasted three years.

The workers demanded better working conditions, but Lord Penrhyn wouldn’t budge an inch, wanting to run the quarry by his rules alone. Eventually the labour force succumbed and were forced back to work as the alternative was starvation.

This was a landmark strike and is often blamed for the start in the decline of the Welsh slate industry. The truth though is that before this event there were telling signs and evidence that the industry was on the decline.

In 1964 the quarry was sold to Sir Alfred McAlpine and Son company. They ran proceedings up until 2007 when it was sold to Kevin Lagan who formed Welsh Slate Ltd.

Part of the quarry that isn’t operational is used for a popular tourist attraction Zip World where terrified members of the public fly across zip lines at a considerable speed above the quarry.

Dinorwig Quarry

Dinorwig was a superquarry and the slate extracted here and Penrhyn was the strongest and most durable in Wales. Dinorwig was an open quarry. One of the techniques that the quarrymen implemented here was to divide the quarry face up into terraces (each 60 to 70 foot in height). This reduced the level of danger from falling rock and enabled more men to work on face at any one time.

In 1787 Assheton Smith in a similar fashion to Richard Pennant of Penrhyn Quarry, amalgamated all the different digging sites on his land into one main quarry. He had grown tired of chasing all the slate extractors for their owed fees.

Like Pennant too he paid the diggers wages rather than collect royalties. When the quarry was at it most industrious, it employed over 3000 men and was one of the largest sites in the world. The slate when prepared and cut would be transferred to the Felinheli dry dock by rail and shipped to other European countries.

The quarry closed in 1969 with 350 men losing their livelihoods. The reasons were mainly due the price of slate being too expensive in comparison to alternatives.

MacAlpine & Son bought the quarry and sold off its assets. Heavy Machinery was brought in to replace a formerly labour intensive industry, leaving the area rife with unemployment problems. Thousands of employees were reduced to merely hundreds.

Dinorwig because of it’s epic and rugged landscape has been the setting for many films recently including the 2010 remake of Clash of the Titans and the George Lucas film Willow in 1987. It is also a popular attraction for photographers that like to capture the eerie atmosphere of the abandoned mine.


The Welsh slate quarries all have a fascinating tale to tell. It is interesting to compare what it must have been like during the period of the industrial revolution, to how the quarries are being used today, either for small scale open-cast extraction with the use of heavy machinery, or as popular tourist attractions. When we handle Welsh slate here at Gifts with heart, preparing products to be sent out as gifts to customers, sometimes now there is that moment of appreciation for all that has come before.


The Ffestiniog quarries by the Snowdonia Welsh government site

Llangolman Slate Quarry wikipedia

Corris Mine Explorers

Penrhyn Quarry wikipedia

Llechwedd Slate Quarry

Penrhyn Slate Quarry

Welsh slate craft by Alun John Richards


North Wales filming legacy

Oakeley Quarry


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