Obma couldn’t reveal too much about his character in the series, but said he played an American, so retains his accent, but the show is 97% in Welsh.
Pobol y Cwm, which translates into English as People of the Valley, is the BBC’s oldest television soap, having first broadcast on BBC Wales on 16 October 1974.
It moved to the Welsh-language channel S4C in 1982, where it currently airs three times a week.
A number of well-known actors and actresses have appeared on the show over the years, including Ioan Gruffudd, Iwan Rheon, Michael Sheen and Alexandra Roach.
The star said he watched Pobol y Cwm, Rownd a Rownd and Newyddion S4C to help him while learning Welsh, so “coming to set after watching these people for years was a strange experience”.
“I believe the news and soap operas are such a good tool for people who want to want to learn a language.”
Recognised for his role in the American supernatural series The Vampire Diaries, Obma also played the role of construction worker Adrian in the fourth and fifth seasons of Netflix’s Breaking Bad prequel, Better Call Saul.