Cwm Craig Ddu is a roadside section found to the east of Llangammarch Wells, along the B4519. A disused quarry (now overgrown) is also present on the hilltop, but fossils can really only now be found along the cutting. Early fossil plants and small bivalves can be collected here. This site is a SSSI, so hammering the bedrock is strictly prohibited.
♦ From Llangammarch wells, head north to the main A483 and continue towards Garth. Just after Garth, take the B4519 south. Pass over the river, through the crossroads and finally round a sharp bend. A little way past the bend, there is a cattle grid with some rocks on the right hand side of the road, and an area to park beside the cattle grid.
♦ Park here and the cutting is immediately on the other side of the cattle grid. Be aware that, very occasionally, cattle and horses may need to use the cattle gate next to where you park.
♦ Providing you do not venture too far from the site, if this situation arises, you will be nearby to move your vehicle.
♦ Ref: 52.115618, -3.517352
FIND FREQUENCY: ♦♦♦ – Small bivalves are fairly common from the roadside cutting, but the early plant remains are found in the main quarry up the hillside, which is mostly overgrown. In addition, collecting is limited due to the SSSI restrictions on hammering the bedrock at this site. However, there is some loose material, but not much.
CHILDREN: ♦♦ – The cutting is situated along a very busy road, with cars frequently exceeding the speed limit. Therefore, this location is not really suitable for children, because the road is too dangerous.
ACCESS: ♦♦♦♦ – The site is easy to find, being right next to the cattle grid, which you cannot miss. Parking is besides the cutting, but be aware that this is not official parking. It is also where cattle and horses need to cross. Therefore, do not venture too far from the site and be prepared to move if needed.
TYPE: – This site is a roadside cutting, which marks the edge of an old, disused quarry, sloping down the hillside. The old quarry is now overgrown, but outcrops of rock are still accessible at lower levels besides the cutting
You will need to examine the rocks carefully, as fossils from this site are very small. The roadside cutting was designated a SSSI due to its importance for primitive vascular land plants. However, these are rare and the higher beds in the old disused quarry containing them are mostly overgrown. Instead, what you are most likely to find are small bivalves within the siltstones. These may be small, but are remarkably well preserved. They can be found almost anywhere, but are mostly collected by splitting fallen rocks or other loose material within the embankment.
The rocks exposed in the roadside cutting are Silurian age siltstones, which are 420myrs old and part of the Pterinea Beds, Wilsonia Shales Formation, Ludlow series. The site is classified as a SSSI, because it contains the fossilised remains of the earliest vascular land plants yet to have been found in the UK. This particular group of plants contain specialised tissues to carry nutrients and water throughout the plant. Plants living today that use this system include trees, grasses and ferns. All the fossilised remains in Cwm Craig Ddu Quarry belong to the genus Cooksonia, one of the most primitive vascular land plants found in the UK.
The only real danger at this site is the speed of cars using the road. Also, take care when splitting rocks, which could fall onto the road and be a danger to cars.
This site is a SSSI, so hammering the bedrock is strictly prohibited. However, you may hammer any loose fallen material. Take paper to wrap your finds in and a magnifying loupe will come in handy, as the bivalves and plants are very small.
This site is an SSSI. This Special Site of Scientific Interest, means you can visit the site, but hammering the bedrock is not permitted.