Blaenau Ffestiniog is a town in Gwynedd, Wales. Once a slate mining centre in historic Merionethshire, it now relies much on tourists, drawn for instance to the Ffestiniog Railway and Llechwedd Slate Caverns. It reached a population of 12,000 at the peak development of the slate industry, but fell with the decline in demand for slate. The population of the community, including the nearby village Llan Ffestiniog, was 4,875 in the 2011 census: the fourth most populous in Gwynedd after Bangor, Caernarfon and Llandeiniolen. The population not including Llan is now only about 4,000.