My road trip around North wales began with Dinorwic slate quarry (or as I prefer Dinorwig). This place has been on my bucket list for a long time and finding myself bored, itching for adventure and in the area (not), I set out for the mountains. Although this place has been covered well throughout its time its still a place of huge importance, shaping the landscape and surrounding areas both physically and economically. Furthermore, even with its extensive online coverage, experiencing the place in person definitely gives a unique sense of atmosphere, scale, and emotional connection that no screen can truly capture.
The history has also been covered extensively, but i try to summarise it as best as i can below:
(please note - The history here has been sourced from other reports including -
@HughieD
@TheTimeChamber
The History:
Dinorwic Quarry lies between Llanberis and Dinorwic in North Wales, spanning over 700 acres. At its height, it was the second-largest slate producer in the world, surpassed only by nearby Penrhyn. Slate extraction began in 1787 when a consortium leased the land from owner Assheton Smith. Although initially moderately successful, the quarry faced financial setbacks due to increased taxes and transport expenses during the Anglo-French War in the early 19th century.
A turning point came in 1809 when a new business partnership led by Smith revitalized operations. The slate vein at Dinorwic runs nearly vertically and lies close to the mountain surface, allowing extraction through a series of terraced galleries. Multiple sites were active during this period, including Adelaide, Braich, Bryn Glas, Garrett, Turner, Victoria, and Wellington, with this phase continuing into the 1830s.
The construction of a 2-foot gauge, horse-drawn tramway to Port Dinorwic in 1824 significantly boosted productivity, improving transport from the higher elevation quarries around 1,000 feet above sea level. However, lower-level quarries—such as Wellington, Ellis, Turner, Harriet, and Victoria—still faced logistical challenges. These were eventually resolved in 1848 with the introduction of the 4-foot gauge Padarn Railway and the Padarn-Peris tramway extension along the lakeside. This line served as the quarry’s main transportation route until its closure in 1961.
Map of Dinorwic Slate Quarry (This was taken from a report done by - @HughieD )
The layout of Dinorwic Quarry has remained largely unchanged since the time of World War One, aside from the expansion of the quarry faces and the deepening of the pits. The site was divided into two main sections, each with its own system of inclines running from the south-west upward toward the north-east.
The Garret section featured nine inclines, labeled A1 through A9, with a total of 20 levels branching off on both sides. The lowest level, Vivian, sat at roughly 600 feet, while the highest, Llangristiolus, reached around 2,000 feet. Incline gradients varied from a mild 1 in 4.1 (such as A3) to extremely steep slopes like 1 in 2.2 (A6 and A7).
To the southeast lay the Braich section, which had 10 inclines, numbered C1 through C10, and also featured 20 levels in total. Sinc Fawr marked the bottom level at around 400 feet, with Llangristiolus Level again at the top. Braich was home to the steepest incline in the quarry—C8—with a dramatic gradient of 1 in 1.9 at its drum house. Altogether, the 40 terraced levels were connected by an extensive internal tramway network.
During its peak in the late 19th century, the quarry employed over 3,000 workers and produced roughly 100,000 tonnes of slate annually, driven by the global demand for roofing tiles, which were exported throughout the UK, Europe, and North America.
Initially, the internal tramways relied on horse power until around 1860, when steam power began to be adopted. De Winton of Caernarfon provided the first five vertical-boiler steam engines, and from 1870 onward, the Hunslet Engine Company became the primary supplier, eventually delivering over 20 engines to the quarry.
Three main classes of locomotives were used. The "Alice" class made up the bulk of the fleet and operated within the quarry itself. The larger "Port" class engines handled work at Port Dinorwic, while two "Tram" or "Mills" class locomotives managed marshalling duties on the Padarn–Peris tram line, which connected the quarry mills to the Padarn Railway.
Even into the 1960s, the quarry operated around 20 locomotives, though most were sold off during that decade. The final four were sold after the quarry closed permanently in 1969.
Photos of the Quarry in use throughout the years - (photos also sourced from @HughieD 's report)
(Sorry if it seems like I am just stealing your report) But i thought I would include these images as the history behind them is very interesting, being a key aspect of how the Quarry became what it is today.
Quarry-men with a loaded ‘flat car’ of slate—known as a ‘slediad’—prepared for transport to the splitting and dressing sheds at Dinorwic Quarry, early 1960s.
Dinorwic slate miners - 1960:
Following World War One, the demand for slate reached its peak and then began a gradual decline. By 1930, the number of workers at Dinorwic Quarry had dropped to around 2,000, and this figure continued to decrease both before and after World War Two. By the 1950s and 60s, extracting slate from the steep rock galleries had become increasingly difficult. This was partly due to nearly 170 years of waste slate being dumped without proper planning, which had begun to collapse into several of the quarry's main pit workings. Combined with the continuing drop in global demand for slate, the future of the quarry—and the Welsh slate industry more broadly—looked increasingly bleak.
The decisive blow came in 1966 with “The Great Fall” in the Garret section of the quarry, which brought production to an almost complete halt. Although efforts were made to restart operations by clearing the debris and building a new access road to the fall site, the amount of usable slate recovered was minimal. All quarrying activity ceased for good in 1969.
Since then, part of the quarry site has been repurposed for the Dinorwic Power Station, a pumped storage hydroelectric project known as “Electric Mountain.” Construction began in 1974 and was welcomed by the local community for the jobs it provided. When it officially opened in 1984, it was hailed as one of the most innovative feats of engineering and environmental design of its era.
The quarry’s former workshops at Gilfach Ddu were taken over by the local council and later leased to the National Museum and Galleries of Wales. Today, they form the home of the National Slate Museum.
As of July 28, 2021, Dinorwic Quarry is now part of the UNESCO World Heritage Site designation for “The Slate Landscape of Northwest Wales.” It is one of six key areas recognized, with Maenofferen listed as the second location under the name “Dinorwig Slate Quarry Mountain Landscape.”
Finally.
The Explore:
The drive into Dinorwig Quarry began and being the little kid I am I was already filled with excitement. The drive wasn't far from breath taking, with the snow capped mountains, Winding roads that carved through the towering peaks and mist that clung to the mountains, I definitely felt a sense of awe. Parking was very accessible, along with the access to this place. No security. The explore around Dinorwig was on board with the drive. Walking around the abandoned quarry nestled in the mountains felt like stepping into a forgotten world—silent, haunting, and strangely beautiful. Nature had slowly reclaimed the site: moss clung to the slate walls and trees stood where I can only imagine machines once roared. The air was still (subtle foreshadowing) and the wind whispered through many of the derelict buildings. Throughout the site, small underground sections can be found with some containing remains of old railway tracks/tram tracks (please correct me if I am wrong). Although to me it was enjoyable to explore, I could only imagine the danger and working conditions these workers once endured.
Anyway onto the photos -
One of the many slate landscapes found throughout Dinorwig. (The scale does surprise you in person)
Snow capped Mountain peaks -
Group of feral Welsh mountain goats 🐐 - Awesome to see! Keeping on the animal theme - Spotted this adorable mother sheep in a field close by. Learnt later that day, a single blue spot means she is carrying a single lamb - cute! 🐑
The flooded Sinc Harriet (a.k.a. Dali's Hole):
To me this tree was very cool - gave me vibes of the faraway trees from the TV show FROM.
The history has also been covered extensively, but i try to summarise it as best as i can below:
(please note - The history here has been sourced from other reports including -
@HughieD
@TheTimeChamber
The History:
Dinorwic Quarry lies between Llanberis and Dinorwic in North Wales, spanning over 700 acres. At its height, it was the second-largest slate producer in the world, surpassed only by nearby Penrhyn. Slate extraction began in 1787 when a consortium leased the land from owner Assheton Smith. Although initially moderately successful, the quarry faced financial setbacks due to increased taxes and transport expenses during the Anglo-French War in the early 19th century.
A turning point came in 1809 when a new business partnership led by Smith revitalized operations. The slate vein at Dinorwic runs nearly vertically and lies close to the mountain surface, allowing extraction through a series of terraced galleries. Multiple sites were active during this period, including Adelaide, Braich, Bryn Glas, Garrett, Turner, Victoria, and Wellington, with this phase continuing into the 1830s.
The construction of a 2-foot gauge, horse-drawn tramway to Port Dinorwic in 1824 significantly boosted productivity, improving transport from the higher elevation quarries around 1,000 feet above sea level. However, lower-level quarries—such as Wellington, Ellis, Turner, Harriet, and Victoria—still faced logistical challenges. These were eventually resolved in 1848 with the introduction of the 4-foot gauge Padarn Railway and the Padarn-Peris tramway extension along the lakeside. This line served as the quarry’s main transportation route until its closure in 1961.
Map of Dinorwic Slate Quarry (This was taken from a report done by - @HughieD )
The layout of Dinorwic Quarry has remained largely unchanged since the time of World War One, aside from the expansion of the quarry faces and the deepening of the pits. The site was divided into two main sections, each with its own system of inclines running from the south-west upward toward the north-east.
The Garret section featured nine inclines, labeled A1 through A9, with a total of 20 levels branching off on both sides. The lowest level, Vivian, sat at roughly 600 feet, while the highest, Llangristiolus, reached around 2,000 feet. Incline gradients varied from a mild 1 in 4.1 (such as A3) to extremely steep slopes like 1 in 2.2 (A6 and A7).
To the southeast lay the Braich section, which had 10 inclines, numbered C1 through C10, and also featured 20 levels in total. Sinc Fawr marked the bottom level at around 400 feet, with Llangristiolus Level again at the top. Braich was home to the steepest incline in the quarry—C8—with a dramatic gradient of 1 in 1.9 at its drum house. Altogether, the 40 terraced levels were connected by an extensive internal tramway network.
During its peak in the late 19th century, the quarry employed over 3,000 workers and produced roughly 100,000 tonnes of slate annually, driven by the global demand for roofing tiles, which were exported throughout the UK, Europe, and North America.
Initially, the internal tramways relied on horse power until around 1860, when steam power began to be adopted. De Winton of Caernarfon provided the first five vertical-boiler steam engines, and from 1870 onward, the Hunslet Engine Company became the primary supplier, eventually delivering over 20 engines to the quarry.
Three main classes of locomotives were used. The "Alice" class made up the bulk of the fleet and operated within the quarry itself. The larger "Port" class engines handled work at Port Dinorwic, while two "Tram" or "Mills" class locomotives managed marshalling duties on the Padarn–Peris tram line, which connected the quarry mills to the Padarn Railway.
Even into the 1960s, the quarry operated around 20 locomotives, though most were sold off during that decade. The final four were sold after the quarry closed permanently in 1969.
Photos of the Quarry in use throughout the years - (photos also sourced from @HughieD 's report)
(Sorry if it seems like I am just stealing your report) But i thought I would include these images as the history behind them is very interesting, being a key aspect of how the Quarry became what it is today.
Quarry-men with a loaded ‘flat car’ of slate—known as a ‘slediad’—prepared for transport to the splitting and dressing sheds at Dinorwic Quarry, early 1960s.
Dinorwic slate miners - 1960:
Following World War One, the demand for slate reached its peak and then began a gradual decline. By 1930, the number of workers at Dinorwic Quarry had dropped to around 2,000, and this figure continued to decrease both before and after World War Two. By the 1950s and 60s, extracting slate from the steep rock galleries had become increasingly difficult. This was partly due to nearly 170 years of waste slate being dumped without proper planning, which had begun to collapse into several of the quarry's main pit workings. Combined with the continuing drop in global demand for slate, the future of the quarry—and the Welsh slate industry more broadly—looked increasingly bleak.
The decisive blow came in 1966 with “The Great Fall” in the Garret section of the quarry, which brought production to an almost complete halt. Although efforts were made to restart operations by clearing the debris and building a new access road to the fall site, the amount of usable slate recovered was minimal. All quarrying activity ceased for good in 1969.
Since then, part of the quarry site has been repurposed for the Dinorwic Power Station, a pumped storage hydroelectric project known as “Electric Mountain.” Construction began in 1974 and was welcomed by the local community for the jobs it provided. When it officially opened in 1984, it was hailed as one of the most innovative feats of engineering and environmental design of its era.
The quarry’s former workshops at Gilfach Ddu were taken over by the local council and later leased to the National Museum and Galleries of Wales. Today, they form the home of the National Slate Museum.
As of July 28, 2021, Dinorwic Quarry is now part of the UNESCO World Heritage Site designation for “The Slate Landscape of Northwest Wales.” It is one of six key areas recognized, with Maenofferen listed as the second location under the name “Dinorwig Slate Quarry Mountain Landscape.”
Finally.
The Explore:
The drive into Dinorwig Quarry began and being the little kid I am I was already filled with excitement. The drive wasn't far from breath taking, with the snow capped mountains, Winding roads that carved through the towering peaks and mist that clung to the mountains, I definitely felt a sense of awe. Parking was very accessible, along with the access to this place. No security. The explore around Dinorwig was on board with the drive. Walking around the abandoned quarry nestled in the mountains felt like stepping into a forgotten world—silent, haunting, and strangely beautiful. Nature had slowly reclaimed the site: moss clung to the slate walls and trees stood where I can only imagine machines once roared. The air was still (subtle foreshadowing) and the wind whispered through many of the derelict buildings. Throughout the site, small underground sections can be found with some containing remains of old railway tracks/tram tracks (please correct me if I am wrong). Although to me it was enjoyable to explore, I could only imagine the danger and working conditions these workers once endured.
Anyway onto the photos -
One of the many slate landscapes found throughout Dinorwig. (The scale does surprise you in person)
Inside some of the many 'underground' sections that cut through the mountains to gain access. Remains of tracks can be found within.
Slate was not extracted underground at Dinorwic; instead, the extensive network of tunnels was constructed to provide access to the open quarry pits. A dedicated team of rock miners worked to drive these tunnels, which also served to drain water from the deepening extraction areas, known as sincs. As new levels were developed and older ones abandoned, many of these tunnels were left suspended above sheer drops—seeming to end abruptly in mid-air.
One such route can be found on the Penrhydd level, where a former tramway skirts the edge of Sinc Penrhydd before entering a short tunnel. This leads onto the gallery beyond, offering a glimpse into the complex and evolving infrastructure of the quarry.
The 'underground' sections of Dinorwig had to be one of my favourite parts - not sure why? But there definitely is something deeply atmospheric and mysterious about them.
Slate was not extracted underground at Dinorwic; instead, the extensive network of tunnels was constructed to provide access to the open quarry pits. A dedicated team of rock miners worked to drive these tunnels, which also served to drain water from the deepening extraction areas, known as sincs. As new levels were developed and older ones abandoned, many of these tunnels were left suspended above sheer drops—seeming to end abruptly in mid-air.
One such route can be found on the Penrhydd level, where a former tramway skirts the edge of Sinc Penrhydd before entering a short tunnel. This leads onto the gallery beyond, offering a glimpse into the complex and evolving infrastructure of the quarry.
The 'underground' sections of Dinorwig had to be one of my favourite parts - not sure why? But there definitely is something deeply atmospheric and mysterious about them.
Blondin tower and hut:
Quick piece of information that I found interesting.
A Blondin tower is part of a specialised type of material rope-way, also known as an aerial rope-way, used in quarries. It's a high wire carriage system that moves materials. The Blondin system is named after the famous tightrope walker Charles Blondin, because it resembles a high wire.
While Charles Blondin is world-famous for crossing Niagara Falls on a wire, what many don't know is how he once tightrope-walked across a reservoir in Birmingham uk. The local area took great pride in Charles Blondin’s daring feat. His tightrope walk across the reservoir became a cherished part of local history, a story passed down with pride through generations. To this day, the community honors his achievement with a statue that stands proudly in one of the main roads entering the area.
Quick piece of information that I found interesting.
A Blondin tower is part of a specialised type of material rope-way, also known as an aerial rope-way, used in quarries. It's a high wire carriage system that moves materials. The Blondin system is named after the famous tightrope walker Charles Blondin, because it resembles a high wire.
While Charles Blondin is world-famous for crossing Niagara Falls on a wire, what many don't know is how he once tightrope-walked across a reservoir in Birmingham uk. The local area took great pride in Charles Blondin’s daring feat. His tightrope walk across the reservoir became a cherished part of local history, a story passed down with pride through generations. To this day, the community honors his achievement with a statue that stands proudly in one of the main roads entering the area.
Snow capped Mountain peaks -
One of my favourite shots from the visit - I just love how the derelict building portrays a sense of solitude to me (just me? okay..)
Group of feral Welsh mountain goats 🐐 - Awesome to see! Keeping on the animal theme - Spotted this adorable mother sheep in a field close by. Learnt later that day, a single blue spot means she is carrying a single lamb - cute! 🐑
The flooded Sinc Harriet (a.k.a. Dali's Hole):
The famous 'secret waterfall' location. Was alluring to see in person.🌊
To me this tree was very cool - gave me vibes of the faraway trees from the TV show FROM.
Quick shot of the mountainous landscapes surrounding Dinorwig quarry. 🏔️🗻
Thank you very much.
Being my first report, there is bound to be countless mistakes so please correct me if so. Thank you for reading - stay safe while out exploring - leave nothing but footprints and take nothing but photos. Happy adventures!
Being my first report, there is bound to be countless mistakes so please correct me if so. Thank you for reading - stay safe while out exploring - leave nothing but footprints and take nothing but photos. Happy adventures!
