Moelwynion

Yr Arddu is a mountain summit found in the Moelwynion in Snowdonia; grid reference SH673507. The height of the summit above sea level is 589 meters (1932 ft). The height was measured and confirmed on March 10, 2007. This summit should not be confused with Yr Arddu (South).

Ysgafell Wen is a subsidiary summit of Allt-fawr in Snowdonia, North Wales. It is the highest point on a broad ridge that stretches to the north-west of Moel Druman, and includes two other summits, Ysgafell Wen North Top. and Ysgafell Wen Far North Top.

Ysgafell Wen Far North Top is a top of Ysgafell Wen North Top in Snowdonia, North Wales. It lies directly to the west of Ysgafell Wen North Top, and rises as a rocky outcrop from one of the dog lakes, Llynnau'r Cwn.

Ysgafell Wen North Top is a peak on a ridge in Snowdonia, North Wales. It lies to the north of the highest summit on the ridge Ysgafell Wen. It is a subsidiary summit of Allt-fawr. The summit is located at the edge of Cwm Edno, an edge that falls steeply into the cwm. Small lakes surround the summit, known as Llynnau'r Cwn (the dog lakes). To the west lies the peak's top, known as Ysgafell Wen Far North Top.

Moel Druman is a mountain in Snowdonia, North Wales and forms part of the Moelwynion. It is a subsidiary summit of Allt-fawr.

Allt-fawr is a mountain in Snowdonia, North Wales and forms part of the Moelwynion group. It is on the internal border of Snowdonia National Park, and overlooks the town of Blaenau Ffestiniog, with its numerous slate quarries, as well as Llyn Ystradau and Ffestiniog Power Station in Tanygrisiau. On the northern slope of Allt-fawr is the Oakeley Quarry, the world's largest underground slate mine. On the southern slope is the large Cwmorthin Quarry. These two mines are joined underneath the summit of Allt-fawr and the extensive chambering and adits are visible on the surface of the mountain where underground workings have collapsed.Between 1974 and 1997, the Gloddfa Ganol tourist attraction operated within the Oakeley Quarry on the south slope of the mountain.

Conglog quarry was a small enterprise situated to the north-west of Tanygrisiau, near Blaenau Ffestiniog in Wales. It was overshadowed by the much bigger Rhosydd quarry a little further to the west. It was active from 1854 to 1910, and was operated by an individual, two partnerships and four separate companies over this period.

Rhosydd quarry was a slate quarry in the Moelwyn mountains, northeast of Porthmadog in North Wales. Small-scale working of the site began in the 1830s, but was hampered by the remote location, and the lack of a transport system to carry the slates to markets. The Rhosydd Slate Company was formed in 1853, and became a limited company in 1856. Transport was made more difficult by the attitude of the Cwmorthin quarry, through whose land the most obvious route to the Ffestiniog Railway ran. A solution was found in 1864, with the opening of the Croesor Tramway, to which the quarry was connected by one of the longest single-pitch cable-hauled inclines in Wales. Huge amounts of money were spent on development work, and the company, unable to make adequate returns, went into voluntary liquidation in 1873. The quarry was auctioned in 1874, and the New Rhosydd Slate Quarry Company Ltd. was formed. Unlike its predecessor, the directors were all Welsh, and three-quarters of the shareholders were also from the local area. The quarry prospered for a while, but then profitability declined, and in 1900, a large section of the underground workings collapsed. The job of opening up new areas was spearheaded by Evan Jones, who nearly succeeded, but was hampered by a slump in the slate industry and the onset of the First World War, when the quarry was "non-essential" and was mothballed. It reopened in 1919, but was in a poor financial position, and was bought by members of the Colman family, better known for producing mustard. They kept it running until 1930, but failed to find markets for the finished product. It was mothballed until 1947, when it was sold, but new plans to reopen it failed, and the pumps were turned off in 1948, after scrapmen had removed much of the machinery. Of the five slate veins in the region of Blaenau Ffestiniog, most of Rhosydd's output was extracted from the Old Vein. The workings started at the West Twll, where the rock outcropped, but the quarry soon developed into underground workings. A series of adits were constructed, to provide access as the mine got deeper, with the lowest at level 9. Trucks moved along this adit by attaching them to an endless chain, driven by a waterwheel. The mine eventually reached level 14, with rock raised by an internal incline to the level 9 adit. At its peak the quarry was one of the largest underground workings outside of Blaenau Ffestiniog, with 170 chambers.

North West Wales (Welsh: Gogledd-Orllewin Cymru) is an area or region of Wales, commonly defined as a grouping of the principal areas of Conwy County Borough, Gwynedd and the Isle of Anglesey in the north-west of the country. These principal areas make up the entire preserved county of Gwynedd, and parts of Clwyd. It is bordered by Denbighshire, in North East Wales to the east, Powys, and Ceredigion in Mid Wales to the south, and the Irish sea to the north and west (as Cardigan Bay). It is the more mountainous, rural, and sparsely populated part of the north Wales geographic region. Settlements include: Bangor, Caernarfon, Colwyn Bay, Holyhead, Llandudno, and Pwllheli. The port of Holyhead serves as the major sea link between Wales and the Republic of Ireland. Snowdonia National Park is located wholly in the area, hosting Snowdon, the largest peak in Britain and Ireland excluding the Scottish Highlands. The area also hosts AONBs (Area of Outstanding Natural Beauty) in the Llŷn Peninsula and Isle of Anglesey, and the Castles and Town Walls of King Edward UNESCO World Heritage Site.

Cwm Dyli is the location of a hydro-electric power station on the southern flank of the Snowdon range in North Wales. At the time it was built, it was the largest hydro-electric power station in the United Kingdom. It is Britain's oldest power station, and is believed to be one of the oldest Grid-connected hydro-electric stations in the world.

The Crimea Pass (Welsh: Bwlch y Gorddinan) is a mountain pass in North Wales, on the A470 road between Blaenau Ffestiniog and Dolwyddelan connecting the counties of Gwynedd and Conwy.

Cwmorthin quarry was a slate quarry west of the village of Tanygrisiau, north Wales. Quarrying on the site started in 1810. In 1860 it was connected to the Ffestiniog Railway. In 1900 it was acquired by the nearby Oakeley quarry and the two were connected underground. In 1970 it closed along with Oakeley. There was small-scale working in the 1980s and 1990s, and the mine finally closed in 1997.