SNPA Strapline

Snowdonia from the Air

Llyn Trawsfynydd

Snowdonia from the Air

The Impact of Industry

The exploitation of the primary resources of Snowdonia has long been a crucial element in the economy of the area, but industrial developments have mostly been sporadic and short lived, dependant on demand and influences from elsewhere. This process started much earlier than is generally realised, with the quarrying of stone for axes in the Neolithic, copper mining in the Bronze Age and iron production from bog ores in the late prehistoric period. The main impact, however, at least on the landscape, has been from the late 18th century onwards. The variety of metal mines were localised in extent and influence and their remains are, in effect, impositions on the previous landscape. In contrast, slate quarrying resulted in a new landscape, peopled by new communities which developed a distinctive culture. Of all the industries slate quarrying has been by far the most significant and for a century or so it was of international importance, employing some 12,000 men at its peak. In addition to the impressive workings themselves there were dams, water-courses, transport systems, port facilities and a wide range of inter-dependant industries and services. The dramatic increase in population in the 19th century led to the appearance of new towns and villages, with their chapels and schools, and in the rural areas to large numbers of smallholdings, with their distinctive houses and field systems. To a lesser extent stone quarrying was also important, but mainly on the fringes of Snowdonia. At their peak, the Graiglwyd and Penmaenmawr quarries employed nearly 1000 men.

The decline of these industries has left a legacy of social and economic problems which are far from being resolved. The impact of industry on the landscape is still seen by some as a blemish to be removed, but attitudes are slowly changing. When the National Park was designated in 1949 the main quarrying areas were still active and were thus excluded. Industrial monuments are now being given statutory protection and the Park Authority and other bodies are trying to consolidate some of the more important remains. Tourism is also playing its part in generating a wider interest and a new form of revenue from the industrial past. There is little doubt that in another century or so the industrial ‘eyesores’ of today will be regarded as being as much a part of the heritage – and exploitation – of Snowdonia as, for example, the Medieval castles.

An extensive archive of surveys of the slate quarries is held at Plas Tan y Bwlch.

Dinorwic quarry

Dinorwic quarry © CUCAP E1 65, 19489

On the flank of Elidir Fawr and overlooking Llyn Peris is one of the largest of the Snowdonia slate quarries. This dramatic Cambridge photograph, taken in 1949, shows the structure of the quarry at the height of its development. The working faces were linked by tramways on the horizontal terraces to the waste-tips, gleaming with freshly dumped slate. At its maximum there were over 50 miles of tramway. Haulage was by horse until the 1870s when steam locomotives were introduced. Slate for processing was sent down one of the two main incline systems to mills located at several points in the quarry. In the late 1890s over 100,000 tons of slate were extracted each year, almost a quarter of the total output from Wales. After some 200 years of working the quarry finally closed in 1969. It lay derelict for some years before being re-used as the site of the Dinorwig pumped-storage scheme, which uses the waters of Llyn Peris and Marchlyn Mawr, to power a vast underground power station.

Capel Rhosydd

Capel Rhosydd © RCAHM 945188-54

Non-conformism was a strong influence in the quarrying community and each village had one or more chapels. There were enough quarrymen and their families living in Cwmorthin for them to have their own chapels. Capel Rhosydd, with its typical round-headed windows, was built by private subscription in 1867. On weekdays it was used as a school. Sadly it was recently vandalised and the roofing slates removed. Capel Cwmorthin lies lower down the valley.

Rhiwbach quarry

Rhiwbach quarry © RCAHM 94-CS-0906

One of the more romantic of the slate quarries lies in a sheltered hollow at the head of Cwm Machno. The workings are in two large underground complexes of galleries. The older one, now flooded, is at the top of the photograph, with its mill just below. Power for these was provided by two waterwheels and flat rod systems. The later mill, centre right, was driven first by steam and finally by electricity. The transport system here is unusual since everything was moved uphill. The incline from the main workings, centre bottom, can be seen rising to the mill level and another long incline rises to the top right of the photograph. From here a tramway meanders for over three miles to the west before descending to Blaenau Ffestiniog by way of the Maenofferen incline system. The photograph shows clearly the sequence of waste tipping from various stages of the development of the quarry. As one of the more remote quarries Rhiwbach had its own village, shop and school (below).

Pentref Rhiwbach

Rhiwbach village © RCAHM 945095-50

Bwlch Rhosydd

Bwlch Rhosydd © RCAHM 96-CS-0815

On the watershed, between Cwm Croesor and Cwmorthin, stand the mill, barracks and stackyard of Rhosydd quarry. The underground workings are all at a higher level, appearing as two spectacular pits high on the flanks of Moelwyn Mawr. The problem for the Rhosydd company was to get their slate off the mountain and until this was resolved development was limited. Early transport was by packhorse through Cwmorthin, but Rhosydd only had a right of bridleway and disputes with the Cwmorthin company prevented the use of carts and limited access to the Ffestiniog railway. Several proposals were made for inclines and a railway via Cwmorthin, but they came to nothing. A dramatic solution became possible after an incline and tramway were built in 1864 for the Croesor quarry. The Rhosydd company was able to build its own tramway to the head of Cwm Croesor from where a spectacular incline descends for nearly 700 feet to the valley bottom, joining that from the Croesor quarry.

Treforys, Cwmystradllyn

Treforys, Cwmystradllyn © RCAHM 965037-50

In the mid-nineteenth century Gorseddau quarry was developed at great expense, but with little reward due to the poor rock quality. On the northern slopes of the cwm this unusual village was built for the workers, consisting of 18 semi-detached dwellings, set out along three streets. The plans seem to have been drawn up in the comfort of a distant office, since they take no account of either the topography or the drainage. Shallow ditches can be seen, no doubt intended to identify garden plots, though the land is quite unsuitable for cultivation. The manager’s house, now demolished, was in the copse adjacent to the tramway from the quarry.


Ynysypandy © RCAHM 935115-47

Lower down the valley this remarkable three-storey mill was built to fabricate slab products from Gorseddau, using power from a large water wheel inside the building. Slate was delivered and returned to the main tramway by the curving siding. The meagre waste tips indicate that little material was actually processed. The mill was purchased by the National Park Authority in the 1980s and the stonework has been consolidated.

Graiglwyd and Penmaenmawr Quarries

Penmaenmawr © CUCAP BO 58, 1948

Graiglwyd and Penmaenmawr Quarries

Braich y Ddinas hillfort © RCAHM 915031-02

Graiglwyd and Penmaenmawr quarries
For nearly two hundred years the very hard granitic rocks of this headland have been exploited for a wide variety of roadmaking and building materials. In the early 19th century beach pebbles were shipped as ballast to Lancashire and used there as cobble-stones. This led to the manufacture of setts, initially from the extensive scree slopes then by the 1830s from quarried rock. Stone was also broken by hand for macadam. The first mechanical crusher was not installed until 1888, using Hadfield’s new manganese steel, the only material hard enough. Concrete slabs were being made in 1897 and a tarmacadam plant was erected in 1912. The main photograph (Penmaenmawr) is a magnificent view of Graiglwyd taken in 1948. By the 1920s the quarry had begun to encroach on the fine hillfort of Braich y Ddinas, seen here in one of the earliest archaeological air photographs from Wales, taken on an RAF training flight.