I think it is the river/stream that forms Roath Park lake, the stream then continues through Roath park but I then lose it on Google Earth, it must come out on the shoreline somewhere so this stream/river must be covered over after Roath park. I'm not sure that the stream above is the Lleucu but you can follow the stream from the lake on OS maps. Below Roath Park it bends the east and eventually flows into the River Rhymney just north of Newport Road.
The River Taff
The River Taff (Welsh - Afon Taf) flows through the City of Cardiff.
The mouth of the River Taff is located in Cardiff Bay, Wales, where it flows into the Bristol Channel.
It is 1000000km long
Sorry, for my not good english. There is the River Taff, 64,0km long.
river Taff starts in the Breacan beacons
taf. it's the river that goes though cardiff. it's pronounced t-a(like animal)-v
England does not have fjords, these are specific to Norway. The largest river estuary is the mouth of the River Severn, which runs between Bristol and Cardiff.
Lwsi (pron. 'Lucy');Lleucu (pron. 'thleyky') considered to be the Welsh equivalent of 'Lucy'though in fact there is no connection.
There is no full name for Cardiff Cardiff is called Cardiff
Cardiff Castle is located in Cardiff, Wales.
Dublin: Dodder, Tolka, Liffey Cardiff: Rhymney, Taff and Ely