5WA Cardiff was a radio service which began broadcasting on February 13, 1923 and ended on May 28, 1923.
At 5pm on February 23, 1923, 5WA Cardiff, a forerunner of BBC Radio Wales, first broadcast from a music shop at 19 Castle Street in Cardiff city centre. Later that evening at 9.30pm Mostyn Thomas, sang Dafydd y Garreg Wen, which was the first Welsh language song to be broadcast. A commemorative plaque records the event. [Wikipedia]