Before the Industrial Revolution and the coming of coal mining in the South Wales coalfield the valley was rural and farmed.
The town’s name is from the Welsh language; ystrad is a wide flat bottomed valley. The termination ach is associated with the names of marshy floodplains of rivers and is also found nearby in the names Llanbradach and Llancaiach.
Ystrad Mynach is a corruption of 'Ystrad-Man-Ach' meaning "valley of the marshy place (man)" and is not apparently derived from the Welsh mynach meaning monk.
Before the erection of defences on the River Rhymney in the 1960s, the town was subject to periodic flooding, as its name suggests.
Amenities and history
The nearby Penallta Colliery was the last coal mine to close in the valley. Other notable buildings and structures are the Ystrad Mynach railway station, opened in 1890, the viaduct, a sculpture to commemorate the area’s industrial heritage, a community hospital, a number of schools, and the Beech Tree, Coopers Arms and Royal Oak pubs.
From 1927 to 1996, Ystrad Mynach hosted the 'F' division headquarters of Glamorgan Constabulary (from 1968, South Wales Police).
Ystrad Mynach railway station was a location for one of Ronnie Barker's ‘’Porridge’’ episodes. Records show that Ystrad Mynach railway station was in existence in 1857, when it was known as Ystrad Junction.
To the north of Ystrad Mynach, is a collection of houses called Tredomen; these houses were built to house the workers of the since-demolished "Tredomen Works". This collection of houses is one of the best examples of socially graded houses in the world - ranging from two-up two-down, to a five-bedroom manor in Park Lane with adjoining servants' quarters.
- Rugby: Penallta RFC, based in Ystrad Mynach. The Rugby Club was inaugurated by a group of miners from Penallta colliery in 1952.
| ("Wikimedia Commons" has material|
about Ystrad Mynach)
- Ystrad Mynach College
- Welsh Coal Mines - check out the local pit history
- An old photo of Ystrad Mynach in 1938
- Gelligaer Urban District Council (1959). The Gelligaer Story. Gelligaer Urban District Council.