Glencastle Bridge

Single-arch road bridge over river, built 1827-8. Bypassed, 2003. Now disused. Part repointed tuck pointed coursed or snecked rubble stone walls between drag edged rock faced rubble stone piers with drag edged rock faced cut-limestone stringcourses supporting parapets having lichen-covered drag edged rock faced cut-limestone coping. Single segmental arch with drag edged rock faced limestone ashlar voussoirs. Sited spanning river with unkempt banks to river.

A bridge erected under the supervision of Alexander Nimmo (1783-1832), Engineer to the Western District (appointed 1822; replaced 1831), representing an important component of the early nineteenth-century civil engineering heritage of Contae Mhaigh Eo [north County Mayo] with the architectural value of the composition, one succeeding a bridge 'of about twenty feet span…swept away by an extraordinary water-spout in June last [1827]' (Nimmo 1829, 2), confirmed not only by the rock faced dressings demonstrating good quality workmanship, but also by the elegant "sweep" of the arch making a pleasing visual statement at a crossing over a minor river: meanwhile, a discreet benchmark remains of additional interest for the connections with cartography and the preparation of maps by the Ordnance Survey (established 1824).