Located next to the top of Tregynon waterfall is a small Iron Age hillfort, built sometime between 2,700-2,000 years ago. The fort is surrounded by a bank and ditch, which would have been taller and the ditch deeper when first built. For extra protection, a wooden fence known as a palisade, would have been added to the top of the bank. Timber roundhouses with thatched roofs would have stood within the fort. The people who lived here would have survived off the land, growing crops and raising livestock. While little information is available about this site, the nearby Castell Henllys is a good comparison. Castell Henllys open-air museum features reconstructed roundhouses with staff acting as Iron Age people, showing the public how these groups would have lived and how the roundhouses may have been designed. Many of the roundhouses have a central fire which would have been used for activities like cooking or craft, while other buildings such as a wooden hut raised above the ground on four posts, would have been used to store goods or food to keep them away from animals.
