Tre'r Ceiri Hillfort

is one of the most spectacular ancient monuments in Wales. The settlement is surrounded by stone walls that are largely intact, and which reach up to in some places. Within the walls are ruins of about 150 stone houses, which would have had turf roofs. During Roman times, it may have housed up to 400 people. Historian John Davies suggests that because the settlement is so far above sea level, the huts served as habitations for summer shepherds who also had winter dwellings in the lowlands.

In modern times it was first brought to popular attention by Thomas Pennant in his Tours of Wales. Its location and importance have attracted visitors for years. The hillfort has recently been the site of conservation work and footpath maintenance. An extensive survey was made in 1956.