Coal mining changed the landscape of South Wales and the demand for timber pit props is one of the reasons why there are so many forests in the Welsh valleys today.
Many people will never have seen where coal comes from but now, thanks to work carried out by the British Institute for Geological Conservation (BIGC), visitors to woodlands near Caerphilly can see a coal seam without having to venture underground.
The BIGC has excavated an embankment in the heart of Wern Ddu woodlands and cut away a nine metre high basin to reveal where a coal seam, known as Rhondda No. 2, rises close to the surface.
A path has been built to the exposed seam and a viewing area allows visitors to see the results of the BIGC’s painstaking work.
Ben Evans of the British Institute for Geological Conservation said, “We excavated the Rhondda No. 2 coal seam at Wern Ddu woodlands as part of our South Wales Coalfield Geo Heritage Network Project.
“We first exposed this coal seam four years ago and, once we had worked out its exact location and depth, plans were drawn up for the best way to get people as close as possible to it.”
The Rhondda No. 2 Seam is about 300 million years old and is named after the numerous outcrops of the same coal found in the Rhondda Valley. It has three layers and lies beneath coarse grained Pennant Sandstone – a stone typically used for building in the South Wales valleys.
Wern Ddu was almost certainly mined in the 1920s and 1930s by the Black Vein Colliery and later by the Caerphilly Brick Company, when the site was worked by opencast methods for clay.
The woodlands at Wern Ddu are managed by Forestry Commission Wales on behalf of the Welsh Assembly Government. Woodland Supervisor Andrew Hobbs said, “Woodlands often contain interesting geological and industrial heritage features and therefore they can offer a stimulating outdoor learning environment.
“By working with the British Institute for Geological Conservation, we have been able to provide local people and visitors with the chance to learn more about the coal mining history of South Wales.”
The Rhondda No. 2 Seam and other geological exposures in Wern Ddu woodlands are easy to find and are a 10 minute walk from Coed Parc y Van car park, Van Road, Caerphilly. Their Ordnance Survey Grid Reference is ST 168 859.
The BIGC is now working with local community group Caerphilly Woodlands Trust and Caerphilly County Borough Council to develop a geological audio trail at the site.
A Foundation Phase and Key Stage 2 Earth Science education pack called Wern Ddu Rocks has also been produced to provide teachers with information and resources to lead a field trip to the Wern Ddu Site of Special Scientific Interest (SSSI). To request a copy, teachers should contact Ben Evans at the BIGC on 028 20573 305.
The work carried out at Wern Ddu woodlands was part-funded by the Countryside Council for Wales.