All that now remains is the motte, which is referred to as Domen Las (traditionally meaning "blue mound" in Welsh).
However, the threatened invasion did not take place, and Turvey claims that Owain's intention may have been to test the resolve of the new ruler.
A motte was constructed at the end of a low ridge running across marshy ground, surrounded on two sides by the confluence of the Dyfi and Einion rivers.
Llywelyn the Great held an assembly at Aberdyfi Castle in 1216 where he supervised the parcelling-out of land in south Wales to the minor rulers of Deheubarth in return for their homage.
In 1230 he began using the style 'prince of Aberffraw, lord of Snowdon' - in essence, a confirmation of his de facto position as prince of Wales.