|Tre'r Ceiri is a hill fort dating back to the British Iron Age, being built around 100 B.C.|
It is one of the most spectacular of Wales' ancient monuments, located on a summit of Yr Eifl. In modern times it was first brought to popular attention by Thomas Pennant in his Tours of Wales. Its spectacular location and importance have attracted visitors for years.
The hill fort has recently been the site of conservation work and footpath maintenance. An extensive survey was made in 1956.