What makes this site particularly important is that archaeologists have been excavating here for over twenty years and thatched Iron Age buildings have been reconstructed on their original foundations.
As a resource for understanding the Iron Age, Castell Henllys is second to none, providing a unique combination of Scheduled Ancient Monument, archaeological excavation and experimental archaeology.
Today, Castell Henllys (Welsh for the castle of the Prince's court) is set within thirty acres of beautiful woodland and river meadows. Introduced by a visitor centre with exhibition and gift shop and explained by interesting interpretation panels, visitors stroll along leafy woodland and riverside paths, explore sculpture trails depicting myths and legends, pass by prehistoric breeds of livestock grazing in fields next to the path (don't miss the Iron Age pigs), before entering the hillfort itself.
Four roundhouses and a granary have been reconstructed on their original Iron Age foundations at Castell Henllys. The first to be built, the 'Old Roundhouse' was reconstructed more than twenty years ago and is the longest standing reconstructed Iron Age roundhouse in Britain.