Allt-fawr

Allt-fawr is a mountain in Snowdonia, North Wales and forms part of the Moelwynion group.

Allt-fawr
Allt Fawr from the Rhosydd quarry
Highest point
Elevation	698 m (2,290 ft)
Prominence	243 m (797 ft)
Parent peak	Moelwyn Mawr
Listing	Marilyn, Hewitt, Nuttall
Coordinates	53°00′27″N 3°58′02″W
Naming
English translation	big slope
Language of name	Welsh
Pronunciation	Welsh: [ˈaɬt ˈvau̯r]
Geography
Allt-fawr Gwynedd, Wales
Parent range	Snowdonia
OS grid	SH681474
Topo map	OS Landranger 115

Listed summits of Allt-fawr

Name	Grid ref	Height	Status
Cnicht		689 m (2,260 ft)	Hewitt, Nuttall
Moel Druman		676 m (2,218 ft)	Hewitt, Nuttall
Ysgafell Wen		672 m (2,205 ft)	Hewitt, Nuttall
Ysgafell Wen North Top		669 m (2,195 ft)	Hewitt, Nuttall
Moel Meirch		609 m (1,998 ft)	sub Hewitt

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.^[1] On the northern slope of Allt-fawr is the Oakeley Quarry, the world's largest underground slate mine.^{[citation needed]} 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.^[2]

Between 1974 and 1997, the Gloddfa Ganol tourist attraction operated within the Oakeley Quarry on the south slope of the mountain.