Blaenau is a small village situated approximately a mile and a half south west of Llandybie. On the first edition of the 6inch OS maps, published in 1883, there is nothing in the area except a smithy, an 'old coal pit' and some scattered farms. Little had changed by the second edition, published in 1901. By the third edition, published in 1921, there was evidence of more development. Two Sunday schools had been built (Peniel Welsh Independent chapel - NPRN 97168, and Bethel Welsh Calvinistic Methodist chapel - NPRN 6380). The village had also acquired a school building (NPRN 418033). The sudden growth of Blaenau in the early part of the twentieth century may have been linked to the Cilwern Colliery, on the north eastern edge of the village. Like the school and Sunday Schools, this colliery appears for the first time on the 3rd edition of the OS 6inch maps.
The village continued to expand into the 21st century, primarily in a linear fashion along the Penygroes Road (B4556). Most of the houses appear to have been built in the 20th and 21st centuries. Although the colliery and both Sunday schools have now closed, the village primary school remains open, educating approximately sixty children aged three to eleven through the medium of Welsh. Blaenau also has a public house called the Badgers, after which the village rugby football club is nick-named.
Sources: modern and historic map; google street view; Estyn report on Ysgol Blaenau, published in 2016
M. Ryder, RCAHMW, 26th November 2018.