Llechwedd Slate Cavern

Llechwedd Slate Mine

Useful Information

Location: Blaenan Ffestiniog, Merioneth
Open: MAR to SEP daily 10-17:15.
OCT to FEB daily 10-16:15.
Closed on Boxing Day, 25-DEC, 01-JAN. [2007]
Fee: Adults GBP 9.25, Children GBP 7, Pensioners GBP 7.75.
Groups: Adults GBP 7.95, Children GBP 5.95, Pensioners GBP 7.
Classification: MineSlate Mine
Light: LightIncandescent Electric Light System LightSon et Lumière
Dimension: L=40,000 m, D=305 m, 16 floors.
Guided tours: Miners' Underground Tramway tour: L=800
Deep Mine tour: Steps=132, D=25 min.
Address: Llechwedd Slate Cavern, Blaenau Ffestiniog, Gwynedd, LL41 3NB, Tel: +44-1766-830306, Fax: +44-1766-831260 E-mail: contact
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.


1846 Llechwedd Slates Mines begun by John Whitehead Greaves.
1972 opened to the public as 2 ft (610 mm) narrow gauge Miners' Tramway under the name "Quarry Tours".
1979 Deep Tour or Deep Mine opened to the public.
1980 awarded the "Silver Otter" award from the British Guild of Travel Writers.
1992 Deep Mine displays upgraded with audio-visual technology supplied by Eurodisney.
2014 Victorian Mine Tour opened combining the funicular, the tunnels from the two previous tours and some tunnels newly opened to the public.


The rocks mined here were slates, which were used as roofing slates. The slate is conveniently bedded between layers of granite, giving integral strength to the rock, which was a big help for mining.


The part of the mine, opened to the public in 1972 is today called Miners' Underground Tramway. It is the oldest part of the mine from 1846 and completely at surface level. The tour starts in an original slate slabbing mill of 1852. The visitors board a train and ride into a tunnel, hauled by battery-electric locomotive.

Later, in 1979, the Deep Mine tour was opened. The visitors get helmets for this tour. Britain's steepest passenger railway, with a gradient of 1:1.8 or 30°, brings the visitors to a lower floor of the mine. It is actually a funicular, not a railway. Two floors of the mine are visited in a circular tour, highlight is a subterranean lake. The tour is accompanied by harp music, called son et lumière. The music was composed by Siôn Dolgarregddu who was born in 1844 and worked in the mine from 1856. The harp is played by Elinor Bennett.

On the surface, many buildings like the old smithy and the slate mill complete the experience.

This is Britain's newest show cave, only being opened to the public in the spring of 1972. The Llechwedd Slate Caverns form part of the famous Llechwedd Slates Mines, begun by John Whitehead Greaves in 1846. The underground workings now consist of over 25 miles of tunnels connecting vast chambers, from which the slate has been extracted. These workings extend a total depth of 900 feet. The section now open to visitors is part of the original level opened in 1846. Different lighting techniques are employed to bring out the natural beauty of the rock. In one area, to recapture the original atmosphere of the mine, a journey is made on a tramway, on which battery-operated electric locomotives haul specially designed passenger cars. The track is on level ground throughout - there are no cages or inclines involved - and emerges into daylight three times during the half mile round trip.

Other parts of the mine are still being worked, and it is possible to watch craftsmen using the age-old techniques of splitting slate in the mill - in fact you can even have a go yourself.

Text from: Tony and Anne Oldham (1972): Discovering Caves - A guide to the Show Caves of Britain. With kind permission by Tony Oldham.