Overlooking Bae Abertawe is none other than the impressive structure of Oystermouth Castle (Castell Ystum Llwynarth). A non-native Norman castle, it is one of the more picturesque and stands in a scenic location near Abertawe.
It is believed that the original Oystermouth Castle was constructed sometime in the early 12th century. Like many Norman castles, it is also believed to be built upon what was the location of a native Welsh castle, though this is yet to be proven. It was built by the Normans with the intention of guarding Afon Tawe from the Welsh populations.

On two known occasions (1116 and 1137), the castle was destroyed by the Welsh of Deheubarth. The castle would have been made of timber during this time. The Normans would rebuild the castle following both occasions, though it would be captured by Llywelyn Fawr (Llywelyn the Great) in 1215.
It was following the capture of the castle by Llywelyn, who was forced to vacate it by Henry III of England, when the castle would be fortified in stone by John de Braose.

The castle would pass from noble family to noble family for centuries before falling into ruin – though a rather pretty one, it must be said. Nowadays, it is in the hands of the City and County of Swansea council. It remains a key tourist attraction in De Cymru.
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DIGITAL Welsh Histories Magazine – January 2026
Niklas is the founder, owner, manager, editor, writer, video creator, voice over artist, and so forth, of Welsh Histories. He is passionate about the preservation of Welsh culture; the rejuvenation of the Welsh language and the promotion of Welsh history. Niklas currently resides in Pune, Maharashtra, with his beloved wife.

