Many towns along the Welsh/English border have the prefixed letter Y (the) The Welshpool - The Newtown (Y Drenewydd).
Phonetically Y TRALLWNG might be sounded as Uh TrA - soft hissing sound ([LL]tongue on roof of mouth and air coming out the sides of the mouth) - WooUng.
I have added people to make it look busy. It may in fact be a busy town, for it has plenty of lively shops. Its just that I am not used to seeing people there. It has the air of having been a very prosperous farming town at one time with lots of history. Even now it has a very large, newly rebuilt livestock market.