A number of places still identifiable in the Shropshire landscape today are mentioned alongside Pengwern in this poetry. The exact location of "Llys Pengwern" - the Court of Pengwern - is not known, and the problem is compounded by the fact that several other Pengwerns exist in Wales (e.g. near Denbigh in north Wales). A tradition, recorded by Giraldus Cambrensis in the late 12th century, associates it with the site of modern Shrewsbury (although that town has been known as "Amwythig" in Welsh since the Middle Ages). A number of alternative locations have been proposed. A more recent suggestion is the "Berth", a dramatic hillfort at Baschurch, but the archaeological evidence shows only the Iron Age fort with possible Roman reuse. Wroxeter, the former Roman town of "Viroconium Cornoviorum" lies in proximity to these places. Archaeological evidence suggests that Wroxeter continued in use after the Roman withdrawal and was only finally abandoned in about 520 when it had become indefensible as the last vestiges of Romano-British central government broke down. Another theory is that the earthworks under Whittington Castle may be Pengwern.