Slate Industry of North Wales


Slate Industry of North Wales is part of the Tentative list of United Kingdom in order to qualify for inclusion in the World Heritage List.

These sites are testament to the slate industry in North Wales that has been present from the Roman period onwards. The industry grew significantly in the 18th century before reaching its zenith 19th century, when these Welsh quarries provided roofing materials and slate products throughout the world. They also innovated the associated technologies of quarrying and transport infrastructure were also exported worldwide. Included in the nomination are 6 quarrying landscapes and their associated transport infrastructure, including the renowned Ffestiniog railway, and also the educational institution built for miners which is now part of Bangor University.

Map of Slate Industry of North Wales

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The coordinates shown for all tentative sites were produced as a community effort. They are not official and may change on inscription.

Community Reviews

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Austria - 23-Dec-20 -

Slate Industry of North Wales (T) by Hubert

“To steal a mountain” was the title of the introductory film in the National Slate Museum in Llanberis. And if you look at the mountainside above Llyn (Lake) Peris, you understand how this is meant: the Dinorwic quarry gapes like a giant wound in the scenic landscape of the Snowdonia Mountains. I was torn between two opinions. On the one hand: the slate industry is not yet represented on the WH list, and Wales has a large number of original remains to fill this gap. So clearly pro inscription. But on the other hand: Should this ugly industrial landscape really be preserved? Or should we hope nature recaptures all of this as soon as possible?

The Slate Industry of North Wales is scheduled for nomination in 2021. In May 2017 we spent five days in Llanberis. Our main goal was to hike in Snowdonia National Park, but there was also enough time to visit some sites of the slate industry. There is not much left in Llanberis from the heyday of the slate industry. Today the village at the foot of Snowdon summit is a centre for hikers and other outdoor activities in the national park.

The National Slate Museum was a good introduction to the topic of slate production. The museum is located at the former workshops of the Dinorwic quarry. Most interesting was the demonstration how the slate was splitted and cut to roofing shingles.
At the roundabout not far from the Slate Museum, a zigzag trail leads up to the Dinorwic quarry. The quarry was once the second largest slate quarry in the world, only the nearby Penrhyn quarry being larger. Dinorwic was closed down in 1969, the lower part is now used by a hydroelectric power plant, but the upper terraces are accessible (upper photo). On the way up we saw remains of machinery, winches and rail tracks, and ruins of quarry buildings. As an example: the Anglesey Barracks (lower photo), a double row of terraced cottages where the quarrymen stayed during the working week. Even from the ruins, you can sense the harsh and cramped living conditions in the 19th century. And we saw discarded rock, tons of it, slate wherever you look. No trace of "nature is recapturing the abandoned place".
The view from the top over the quarry, the lakes and the Snowdon Mountains is great. We enjoyed exploring the remains of the abandoned quarry. The hike was about 5 kilometers long with an altitude difference of about 500 metres, in most parts over slippery slate.

Only one day of heavy rain out of five days in the national park - not bad for North Wales in late May. And I wasn't unhappy about the one day with bad weather because I was able to convince my friends to visit another site of this TWHS: the Llechwedd Slate Caverns near Blaenau Ffestiniog. Here, the slate was mined underground, in contrast to the open quarries of Dinorwic and Penrhyn. This could be due to the fact that the deposits originate from different geological periods: Llechwedd from the Ordovician, the more northern deposits around Llanberis from the Cambrian.
A narrow-gauge tramway descends 150 meters below ground to the slate caverns. The tour leads through a network of tunnels and large chambers. The slate mine resembles more a salt mine than the narrow galleries of a coal mine or an ore mine. However, the first thing we saw when we got off the railway were boxes of cheddar, Cavern Cheddar. The cheese is matured down in the mine for 11 months. You can buy it in the souvenir shop, and of course, we tasted it. So you can choose between two souvenirs: the Cavern Cheddar (more tasty) or a roof shingle made of slate (longer durable).

We had short stops at a few other locations that might be part of the nomination: the ruins of the Ynysypandy Slate Mill, a large mill building and freely accessible; the Dorothea quarry in the Nantlle valley, another abandoned slate quarry; and Port Penrhyn, once the main port for the shipment of slate, but today nothing reminds of that time.

In recent years industrial and technical sites have been quite successful at the WHC sessions. Thus, I would expect inscription for the Slate Industry in North Wales in 2021.

Thomas Harold Watson

30-Apr-20 -

Slate Industry of North Wales (T) by Thomas Harold Watson Of all the tentative listed sites I have visited as of yet, this is easily the most deserving of a whole heritage status. The slate industry is not currently represented atall by UNESCO and after driving through towns completely made with slate (the roofs, fences, gravestones and pretty much anything else you could think of) we visited the mines, which were even more fascinating. I don’t often want to return to many places, but this is one I definitely look forward to going back to, even if it’s just for their underground trampoline park! My 2 year old daughter and newborn son were also allowed down with my partner and I, but the whole time we felt completely safe, so do not worry about anything if visiting!

Read more from Thomas Harold Watson here.

Els Slots

The Netherlands - 11-Mar-20 -

Slate Industry of North Wales (T) by Els Slots

The Slate Landscape of Northwest Wales is the UK’s nomination for 2021. It will be a serial site with 7 components. Each of the components consists of a number of ‘elements’ – the most noteworthy “physical features which embody the attributes of Outstanding Universal value”. That value is to be found in (ii) the technology transfer to continental Europe and the USA, (iv) the dramatic impact of large-scale exploitation of natural resources and (v) the legacy of the industrial workers and their settlements. Its official name has been changed from “Slate Industry ..” to “Slate Landscape”, obviously emphasizing the cultural landscape approach.

I visited one of the components, the town of Blaenau Ffestiniog, on my way to the Gwynedd Castles in 2011. I’ve got a couple of photos left, but I must admit that I did not write up anything about the side trip and I can remember almost zero. What I see when I look at those photos again is a town that could only be in the UK: straight rows of similar stone houses (cheap housing for the quarrymen), a fish and chip shop, an Anglican church (they call it “Church of Wales” over here), a WWI memorial. It is surrounded by steep natural hills and man-made waste dumps. All photos appear to be taken in black-and-white as grey is the prominent colour of it all (including of course the slate roofs).

At the center of the town lies a railway station, which is the terminus of a narrow-gauge heritage railway. It was originally built to connect the quarries with the sea. The railway tracks and the “sense of arrival” (when doing so by train) are prominent features in the WH nomination. Most of the photos that I still have are railway related, so it must have been the town’s most impressive sight. In hindsight, St. David’s Church (now advertising bilingual services but in the past all churches preached in Welsh) and the market hall with interesting architecture might have warranted a closer look.

Desk research in 2020 reveals that there is a (slightly outdated?) nomination website available in Welsh and English, and the Management Plan can be found online as well. It is all well-presented and I don’t think there will be many objections getting it inscribed. But just as with my short visit, the presentation does leave an aftertaste of “Is this special enough?”. There was no element mentioned where I’d would be really interested enough to go back for a ‘proper’ visit. There’s the social history of course and the exploited landscape - this recent work might be an interesting read to get a better feel for the Welsh Slate history. Excerpts are readable for free online.

In ICOMOS’s Filling the Gaps document of 2005, that had the goal of identifying under-represented categories, post-Industrial Revolution technological properties located in Europe and North America were considered “overwhelmingly” present already. However, in the years since several more have been added to the List. Among those is for example the Cornwall and West Devon Mining Landscape which is geographically and thematically close to the Welsh Slate Industry Landscape. One of its arguments in the comparative analysis was that tin mining was not represented yet, and – indeed - slate mining also isn’t. But do we really need all imagineable resources represented?

Jakob Frenzel

Germany - 10-Jun-18 -

Slate Industry of North Wales (T) by Jakob Frenzel

March 2018 - In the afternoon we reached Snowdonia. Amazing Nationalpark and still covered in snow.

All houses in the valleys were covered with slate and even the walls were made from slate. Certainly an important raw material in that area and we learned Wales is the biggest exporter of slate. We took a short hike along Dinorwic Workings and discovered the impact of the industry here.

Next morning we still visited Bangor University.


UK - 29-Oct-17 -

Slate Industry of North Wales (T) by Solivagant

I don’t normally review sites from UK but, having just returned from a visit to the “Slate Industry of N Wales” T List site, I was surprised to note that it has not yet been reviewed at all. Since it is relatively easy to take in whilst visiting Gwynedd Castles and Pontcysyllte Aqueduct, WHS travellers might find the following info of use.

Just as S Wales is synonymous with “Coal”, N Wales is significantly linked to “Slate”. In the 19th C, Welsh slate roofed the burgeoning housing of London and elsewhere in UK and was also exported around the World - peak production was around 1831-78. Nowadays only some small scale production continues. The 7 areas identified for possible inscription follow a pattern set by the Devon/Cornwall mining site WHS - a number of mines, together with some towns/villages, often in the form of a cultural landscape, a port and some railways. For good measure add a 19th C Industrialist’s stately home and a university founded for the working class. These are scattered across N Wales and you will have to decide where to put your time and effort! It is perhaps worth mentioning a couple of things about slate extraction – first it can be carried out “open cast” in quarries or underground in mines. Both are represented within the 7 areas – our choice was to see an open cast example. These are spectacular in size when viewed in terms of the technology available and the humans who created them. Having recently visited 2 WHS silver mines in Slovakia and Poland we didn’t feel the need for another underground trip! This may have been a mistake since the underground quarries contain huge caverns with lakes unlike the small tunnels of the silver mines! Second, the process of producing 1 tonne of good slate “tile” generated around 9 tonnes of waste. This latter was dumped on the hillsides so, as well as vast “holes” created by the extraction, you get enormous spoil heaps.

We concentrated on “Welsh Slate Museum. Dinorwic Workings”. Dinorwic was the second largest quarry and is situated in the heart of Snowdonia just outside the honeypot location of Llanberis. Here walkers and climbers gather and the Snowdon mountain railway sets off up Wales’s highest mountain (a mere 1085 m high but not to be underestimated on some of its routes and in some weather conditions). The quarry’s 19th C engineering workshops have been turned into the “National Slate Museum” of Wales. This is “Free to enter” (but £4 to park a car), and is well worth visiting to help understand what you see around you and the working conditions and culture of the miners. The quarry contained 2 main areas and each has left a giant gash in the mountain face (photo). Up the mountain-side are a series of levelled areas leading to ever higher quarry “faces” which allowed slate to be extracted from multiple levels at the same time. It was reduced in situ to standard size roof slates (men only got paid for "good" finished slates and worked as small teams covering all tasks from initial extraction. They then shared the final payment). Waste was dumped and the slates were moved from each levelled area to “ground” level on rope inclines, one of which has been restored (look for “V2 Incline”). From there it was transported the c8 miles to the port by narrow gauge (2 ft and later 4ft) railway. This has been reconstructed as a “tourist attraction” running alongside Llyn (= “lake”) Padarn but adopting the narrow internal quarry gauge and using reconditioned quarry locos. The faces themselves have become a climber’s “Mecca” offering a wide range of climb difficulty through to some which have only been completed a handful of times. At the foot of the mountain next to the mining museum the lowest levels have become a lake deep enough (18m) to be used as a scuba diving training area. There are numerous walks in the area including some which ascend the quarry by footpath and lead to some quite atmospheric un-restored working areas with rusting equipment which looks untouched since the last miner left it over 50 years ago! Have a look also at the “hospital” dating from 1860 and paid for by the workers’ own contributions – a “mortuary” building is next door! We parked for free at 53.115489, -4.113017 from where there is an attractive 15-20 minute walk to the Slate Museum which provides fine views of the quarry, the lakes and also a chance to visit the 13th C Castell Dolbadarn which was the highly romanticised subject of a painting by JMW Turner. The museum has numerous displays set in the original “rooms” e.g the Workers’ canteen, the largest working water wheel in UK, a foundry etc etc and provides demos of e.g Slate splitting. Although it also has a row of miners’ cottages transported from another location it is not primarily a “skansen” consisting of such gathered examples. It and nearby walks could easily fill 3 hours or more.

The other major northern “quarry” identified for inscription is at Penrhyn in the Ogwen-Cegn Valley section (situated south of the Slate mining town of Bethesda - it isn't clear if that town itself would be included). This was even bigger than Dinorwic (“At the end of the nineteenth century it was the world's largest slate quarry; the main pit is nearly 1 mile (1.6 km) long and 1,200 feet (370 metres) deep, and it was worked by nearly 3,000 quarrymen.”) and still employs around 170. Its main “up front” visitor attraction is Europe’s longest and fastest zip wire which travels for over 1 mile over the quarry hole and lake. But there would appear to be some interesting walks as well all the way from (or to) the Slate port of Port Penrhyn, taking in Penrhyn Castle built for the owner of the mine. The structure, built around a 14th C fortified manor house, is considered a particularly fine example of early 19th C “mock Castles” and reflects the monies made from slavery and slate by the Pennant family. You could also take in Bangor University’s Neo-Gothic building from 1911 which seems to be intended for inclusion. But I am not sure it would be worth it – we just looked at on the Bangor skyline. The university was founded in 1885 but its original home has been demolished and its tangible connection to the rest of the site is perhaps a bit thin (E.g this report of the opening of the new building “there was then a procession to the college including 3,000 quarrymen (quarrymen from Penrhyn Quarry and other quarries had subscribed more than 1,200 pounds to the university)”).

Instead we travelled south east around 27 miles to the Ffestiniog Slate Landscape. Here there are several more “pay to enter” attractions – the underground mine visit, another (!) zip-wire and an “off road Quarry Explorer” – namely a 4x4 army truck to take you to the top of the quarry. These are not "cheap" - a standard underground tour is £20 though, if you plan ahead and book/take an early one, this price is halved. Even if you don’t want any of this (we didn’t!), the town of Blaenau Ffestiniog itself is worth visiting. It was only created in the early 19th C and is a “slate town” par excellence, a raison d’etre it is trying to replace with tourism. Around 85% of the population are Welsh speakers. It lacks significant buildings, but still provides an authentic atmosphere with its remote setting in wild countryside within which the grey spoil heaps almost “disappear”. Indeed if one knew the likely boundaries intended for the “slate landscape” there are a number of ghost slate villages in the surrounding hills which could be worth walking to (Cwmorthin looked interesting on a flyer we were given). The T List entry suggests that the narrow gauge steam railway which terminates at the town would be included. This makes its way up the 950ft from the coast at Porthmadog via a twisting route through attractive scenery with regular services provided by authentic steam locos. We didn’t take the train but did stop off at Tan-y-Bwlch station, where “up” and “down” trains pass each other on this single track line, in order to see 2 trains at the same time! The T List entry given to UNESCO also refers to the intention to include the “early hydro-power station”. But why – it only dates to 1963 and its prime factor of interest is that it is a “pumped storage” station? This uses more energy than it creates but it can produce 360 mw “on demand” and thus saves on “peak power” investment. It doesn’t really seem relevant to the OUV of the site?

So - what are the chances of inscription? Well, having experienced many of the other “Industrial Heritage” WHS around the World, I don’t see that this one is any less valid – indeed rather the opposite! Slate quarrying isn’t represented at all (Syracuse has significant ancient stone quarries and Italy also has the Carrara Marble Quarries on its T List though it would appear that it intends presenting these also as an archaeological site rather than as an industrial one), whilst there are numerous Silver mines! I found the Dinorwic location particularly worthwhile both for its museum, located in an authentic building and other remains, particularly the more remote ones. In common with many UK WHS there is a fair degree of “commercialisation” in the presentation of some of the “experiences” at some locations but I don’t see that these interfere with the overall OUV. The potential nomination has a “Web Site” and this contains an assessment of potential economic outcomes from a successful bid (It is interesting to see what the “drivers” are behind local support for the WHS initiative (i.e Jobs!) but, when I spoke to several “locals” in Blaenau Ffestiniog, none of them was aware of the intention to gain WHS status! I also found the arguments in the report for the potential economic benefits of inscription rather unconvincing – using Vigan as a benchmark hardly seems relevant!) The only time scale info is this quote “A technical evaluation of the bid was presented to the DCMS in November 2015 for consideration by a panel of heritage experts. We received constructive and positive comments on the bid in early 2016 and are now working towards developing and strengthening the necessary documentation with a view to gaining a date from DCMS for final submission of papers to UNESCO.” With Scotland having been successful with the Forth Bridge in 2015, England with the Lake District in 2017 and apparently also pursuing Jodrell Bank for 2019 it would seem that Wales would have a good argument for progressing the Slate Nomination ASAP thereafter.

Full Name
Slate Industry of North Wales
United Kingdom
Nominated for
2012 Added to Tentative List

Site about the World Heritage bid

The site has 7 locations

Slate Industry of North Wales: Ogwen-Cegin Valleys (T)
Slate Industry of North Wales: Welsh Slate Museum. Dinorwic Workings (T)
Slate Industry of North Wales: Nantle. Moel Tryfan (T)
Slate Industry of North Wales: Gorsedda quarry tramway and worker settlement. The Ynysypandy slate mill (T)
Slate Industry of North Wales: Ffestiniog slate landscape (T)
Slate Industry of North Wales: Southern Gwynedd quarrying landscape and transport systems (T)
Slate Industry of North Wales: Bangor University (T)
WHS 1997-2021