Recent investigations at Ffos-y-fran have identified the remains of three rectangular structures believed to be a part of the remains of the 19th century Penydarren Brickworks, adjacent to the Sarn Howell Pond. The two eastern buildings are aligned east to west and are roughly comparable in size (c7.5m x 4.5m), whilst the western building is only partially exposed. All three buildings form part of the brick manufacturing process from the preparation of the raw material through to moulding/setting, drying and firing. The brickworks is likely to have served the Penydarren Colliery, including buildings associated with its incline tramroad to the GWR line at Cwm-bargoed and numerous small scale local industrial concerns. The brickworks is thought to have had a comparatively short life since it is shown in use on the OS 2nd Ed map (1901) but retired by the publication of the OS 3rd Ed map (1920).

During the evaluation of an area to the south of the site on the edge of the Taff-bargoed Valley we have discovered a large mound or cairn of stones directly beneath the topsoil. The cairn appears to contain a centralised rectangular arrangement of inverted stones, which may be a Bronze Age burial mound. However, further investigation is needed to prove its provenance. Bronze Age round barrow cairns are a type of monument which can be found broadly distributed on the nearby Gelligaer Common.  For more information on cairns visit the Prehistoric Funerary and Ritual Sites in Southeast Wales project pages on the GGAT website http://www.ggat.org.uk/cadw/fun_rit/english/cairn.html

In an area adjacent to the supposed cairn, several features have been identified, which include a possible cremation burial. A small quantity of burnt bone was recovered from a shallow pit that was surrounded by an area of burning. Although highly probable as a burial, the recovery of worked pieces of flint in the immediate vicinity along with more evidence of burning may indicate that this is food waste rather than funerary in origin.