The Iron Age Hill Fort at Tre Ceiri on the Lleyn Peninsular in North Wales dates back to 200 B.C. This site ,“Town of the Giants” is one of the most spectacular ancient monuments in the British Isles. This site was used by the Celts during the Roman Invasion of North Wales but the legionnaires never were able to take it over on account of the heavy barrage of stones pelted at them from above! Looking out to the west, over the Irish Sea the Isle of Man can be seen and on a clear day Ireland. Wild Wales Walkabouters in early June atop Tre Ceiri.