Long before the Normans began their extensive castle-building program, which ultimately resulted in the subjugation of Wales (at least in theory), the promontory site now occupied by modern Aberystwyth was recognized for its defensive qualities. Iron Age settlers fortified the hilltop called Pen Dinas with a huge fortification, one of the largest Iron Age hillforts in the region. Today that hillfort dominates the skyline as you approach Aberystwyth from the south. Not only does it create an air of mystery, it also reminds us of the skills of its ancient builders. It remains a remarkable testimony to the Iron Age people that they could construct such a formidable hilltop fortification with their primitive technology. That it has survived over two thousand years makes their accomplishment all the more impressive.

Not until the Normans marched into West Wales were castles in the true sense of the term built at Aberystwyth. The first was a ringwork castle, built by Gilbert de Clare, a prolific castle-builder in the early 12th century. Curiously, the earthen castle was the scene of much intrigue, as the Welsh and Normans repeatedly vied for control of the site. Traces of the stronghold, known as Castell Tan-y-castell, persevere alongside the River Ystwyth.

Inevitably, the earth and timber defenses proved too vulnerable and a new site was chosen for a castle in Aberystwyth. This time the Welsh, led by Llywelyn the Great, built the castle in this seaside spot. Like its predecessor, the castle exchanged hands several times, and finally became useless against advances in weapons technology.

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