Of the structure whose origin is ascribed to Meyler Fitz Henry, but completed by Archbishop Henry de Loundres, A.D. 1223, a portion may possibly be concealed beneath the piles of modern edifices which represent the present Castle of Dublin. The Castle presents little that is of interest to the architectural antiquary, except he finds it in the massive walls of the Record Tower, the oldest portion of the group of buildings between the Castle yards. * * * * * _Bridges._--That the Irish at an early period were in the habit of constructing bridges and causeways over rivers, or from the mainland to an island, or from one island to another, is a fact recorded in the ‘Annals’; and we are not wholly without some existing remains of that interesting class of structures. We read that in A.D. 1054 a bridge was built over the Shannon, at Killaloe, by Turlogh O’Brien. This work was no doubt of timber. It had probably been long decayed or destroyed when Richard de Clare obtained possession of the greater part of that county which still bears his name. But the ford was not so easily obliterated, and Killaloe was for a considerable time called ‘Claresford’ by the English. The little island of Begerin, near Wexford, was formerly connected with another island by a causeway, described by Mr. G. H. Kinahan as consisting of two rows of oak piles, set four feet apart, with about five feet between each pair. ‘On these piles,’ he remarks, ‘there would seem to have originally been longitudinal and transverse beams.’[131] St. Ibar, who died in A.D. 500, had a church and monastery in Begerin, so that there is every probability that this bridge or causeway may be referred to a very early date. The islands of Devenish and Inismacsaint, in Lough Erne, both of which were monastic sites in the sixth century, had similar communications with the mainland. A number of the piles at the latter island may still be seen when the water is low. Many of the lake-dwellings, or crannogs, were, as we have seen, furnished with causeways connecting them with the mainland, or with neighbouring islets.