Had a fantastic time exploring a few sections of these mines with Le Kwan, Lenston, Rawski and Crooner. Thanks so much guys for having us, really enjoyed it. No awards for the photography here unfortunately but some amazing colours down there and some of the industrial heritage remains there in a very rusted and delapidated state which works for me. 
I've totally nicked some info and history from http://www.fforestfawrgeopark.org.uk, sorry.
Silica mines at Pontneddfechan
The area around Pontneddfechan at the head of the Vale of Neath is one of very few in the world where sandstone has been extensively worked in underground mines. But then this is a very special sort of sandstone.
Silica Rock
In the steep walls of the gorges of the Nedd Fechan, the Afon Mellte and the Sychryd are exposed beds of a very hard and pure sandstone which have come to be known as ‘the Silica rock’. It is in fact the lowermost of a whole family of such beds which collectively are termed the ‘Millstone Grit’ – a gritstone is simply a sandstone formed from coarse angular grains of quartz or ‘silica’.
It is the purity of these rocks – almost 100% silica (SiO2) – that made them a target for miners from the 18th to the 20th century. The burgeoning industries of industrial South Wales needed large numbers of heat-resistant bricks to line the furnaces in which copper and iron-smelting took place. Only bricks made from more or less pure silica could stand the intense temperatures without shattering.
The silica rock was worked through a series of adits – horizontal mine passages driven into the side of the hill – both behind Craig-y-ddinas and on either side of the Nedd Fechan upstream of Pontneddfechan.
Dinas Rock Silica Mines
The mines behind Dinas Rock were a rather larger affair than their cousins alongside the Nedd Fechan. Several large entrances are still clearly visible from the path which drops steeply down from the top of Dinas Rock to the Sychryd.
Note that although they are situated on what is now Forestry Commission access land, none of the mine entrances should be approached due to the danger of rockfall.
The underground galleries were very extensive, extending over an area some 1000m x 500m. Parts of the mine are now flooded, others will have become unstable.
The material was transported by a series of tramways and inclines and indeed overhead cables suspended on pylons, down to the valley floor and then onward to the Pont Walby brickworks. The former tramway along the southern side of the Afon Mellte is a modern-day bridleway which allows the route to be traced on foot or pushbike.
In later days the material was taken to a brickworks at Swansea until the whole operation closed down in the 1960s.
Really enjoyed it here, thanks again Kwan and Lenston.
Thanks for looking
I've totally nicked some info and history from http://www.fforestfawrgeopark.org.uk, sorry.
Silica mines at Pontneddfechan
The area around Pontneddfechan at the head of the Vale of Neath is one of very few in the world where sandstone has been extensively worked in underground mines. But then this is a very special sort of sandstone.
Silica Rock
In the steep walls of the gorges of the Nedd Fechan, the Afon Mellte and the Sychryd are exposed beds of a very hard and pure sandstone which have come to be known as ‘the Silica rock’. It is in fact the lowermost of a whole family of such beds which collectively are termed the ‘Millstone Grit’ – a gritstone is simply a sandstone formed from coarse angular grains of quartz or ‘silica’.
It is the purity of these rocks – almost 100% silica (SiO2) – that made them a target for miners from the 18th to the 20th century. The burgeoning industries of industrial South Wales needed large numbers of heat-resistant bricks to line the furnaces in which copper and iron-smelting took place. Only bricks made from more or less pure silica could stand the intense temperatures without shattering.
The silica rock was worked through a series of adits – horizontal mine passages driven into the side of the hill – both behind Craig-y-ddinas and on either side of the Nedd Fechan upstream of Pontneddfechan.
Dinas Rock Silica Mines
The mines behind Dinas Rock were a rather larger affair than their cousins alongside the Nedd Fechan. Several large entrances are still clearly visible from the path which drops steeply down from the top of Dinas Rock to the Sychryd.
Note that although they are situated on what is now Forestry Commission access land, none of the mine entrances should be approached due to the danger of rockfall.
The underground galleries were very extensive, extending over an area some 1000m x 500m. Parts of the mine are now flooded, others will have become unstable.
The material was transported by a series of tramways and inclines and indeed overhead cables suspended on pylons, down to the valley floor and then onward to the Pont Walby brickworks. The former tramway along the southern side of the Afon Mellte is a modern-day bridleway which allows the route to be traced on foot or pushbike.
In later days the material was taken to a brickworks at Swansea until the whole operation closed down in the 1960s.
Really enjoyed it here, thanks again Kwan and Lenston.
Thanks for looking
