Tanygrisiau is a village and area within Blaenau Ffestiniog in the upper end of the Vale of Ffestiniog in the county of Gwynedd, north-west Wales . It can be found along the southern side of the Moelwyn mountain range and dates to around 1750. It joins onto the semi-urban area of Blaenau Ffestiniog, and is in the community of Ffestiniog; located between 650 feet (200 m) and 750 feet (230 m) above sea level.