You can see from this map that this valley was the most built up of the three during 1884. You can see Oakwood and Maesteg-Merthyr Pits marked here.
The Llynfi Valley had a number of pits working through the years and numerous levels (drift mines). The deep pits included:
- Bryn Navigation – sunk in 1890s and closed in 1964
- Garth – sunk in 1864 and closed in 1930
- Coegnant – sunk in 1882 and closed in 1981
- Caerau – sunk in 1889 and closed in 1979
- Oakwood – sunk in 1868 and closed in 1928/9
- St.John’s – sunk in 1908 and closed in 1985 (the last deep mine in the Llynfi Valley)
You can explore this map yourself on the Old-Maps website