The one object of antiquarian interest in the town is the church, planted in the midst of an old _caer_, or fortress, the walls of which still stand in places 16 feet high, and are over 6 feet thick. The enclosure is quadrangular, and measures 220 feet by 130 feet. To what period the walls belong is hard to determine. They are constructed of unshaped blocks of granite rounded by the action of wind and rain, and are set in mortar made of sea-shells. In places they are arranged herring-bone fashion. The construction is too uncouth to be Roman, and the round towers at the angles are not Irish. It is certainly prior to the English conquest. A Norman builder would have disdained to put forth such work, and it is probably a unique specimen of a _caer_ of late British erection. The two entrances are much more modern. This fortress was held by the Gwyddyl against Caswallon Long-hand. Then the walls were of stones set up without mortar, and probably faced with huge granite slabs. Caswallon forced his way in, and slew the Irish king Serigi with his own hand, where now stands Llan-y-Gwyddel in the churchyard. The chapel had a chancel, which has been pulled down, and it was converted into a grammar school in 1748, but is now disused. After the expulsion of the Irish the enclosure became a royal _caer_, and was occasionally occupied by Maelgwn Gwynedd, who made it over to S. Cybi. [Illustration: S. CYBI. STATUE, SOUTH DOORWAY, CAERGYBI] The story of the saint is as follows. Cybi was the son of Solomon, king of Cornwall, and Gwen, the aunt of S. David. He was born between the Lynher and Tamar at Callington, and was sent to school when aged seven. Till he was twenty-seven years old Cybi remained in Cornwall, and then he started on his travels on the Continent. There he made the acquaintance of S. Elian the Pilgrim, and a friendship was formed that was to last through life, though little did both suppose at the time that they would be neighbours in their old age. From his travels Cybi returned to Cornwall, where he became involved in a political disturbance. His father had died whilst he was away, and his uncle Cataw, or Cado, had assumed the rule, but he was succeeded by the turbulent Constantine. The arrival in Cornwall of Cybi gave occasion to an insurrection, and an attempt was made to displace Constantine, and elevate Cybi to the throne. It failed, and Cybi was obliged to fly for his life. He took with him a party of attached disciples and his uncle Cyngar. After a brief stay in Glamorgan he crossed into Ireland, and visited S. Enda in Aran, and remained with him for four years.