Just below the confluence of the Taf Fawr and Taf Fechan, the river is crossed by the Pont-y-Cafnau tramroad bridge. This was probably the first iron railway bridge to be built, and was unusual in that it had three levels. The main deck carried the -gauge Gurnos Tramway, beneath which there was an iron trough to carry water from the Taf Fechan leat, while a second water supply was carried in a wooden launder above the tramway tracks. The cast iron structure was manufactured at the Cyfarthfa Ironworks. On the west bank of the river are the remains of the ironworks, which began operating in 1765. The artifacts include seven blast furnaces, which formed part of the largest ironworks in the world in its heyday. The river runs through the western edges of Merthyr Tydfil, where it is crossed by modern bridges carrying the A4054 and A4102 roads, and by Jackson's Bridge, an early 19th century single span structure that carried the Dowlais tramway and a road.