Clare Island Lighthouse, Clare Island, Co. Mayo

What catches the eye first is the shape: a circular, battered profile that narrows gently as it rises, wrapped near the top by a cantilevered walkway on granite corbels carved with a thumbnail bead moulding, all held in by curvilinear cast-iron railings of a pattern once described as "Serpentine". It is a piece of functional maritime architecture built with unusual care for detail, the sort of structure that rewards a second look.

The lighthouse dates to 1818, raised for the Corporation for Improving the Port of Dublin, the body then responsible for navigation aids along the Irish coast. Its design is attributed to George Halpin Senior, who served as Inspector of Works and Lighthouses for the Ballast Board from 1810 and left his mark on lighthouses around the country. According to one account, Halpin's tower reused the burnt-out shell of an earlier lighthouse built in 1806 to 1807 by John Denis Browne, first Marquess of Sligo, whose family held considerable land and influence in this part of Mayo. The tapering silhouette and the ironwork around the lantern are pointed to as evidence of this inheritance, a structure rebuilt on the bones of its predecessor rather than started from nothing. The lighthouse was still standing in 1838, was restored in 1909, and continued in service until it was decommissioned in 1965, after which it passed out of state hands and was sold in 2008 for continued use as a private residence.

Little of the original working apparatus remains to be seen from outside, but the architectural bones are intact: square-headed window openings with cut-granite sills and lintels frame timber casement windows, and the granite ashlar walls sit on a chamfered plinth. The grounds retain their own boundary treatment, with repointed piers topped by shallow pyramidal caps supporting looped wrought iron double gates, a domestic touch grafted onto what was once a purely utilitarian maritime structure. As a private home, it is not open for casual visits, but its position on the island's coastline and its distinctive form make it a recognisable landmark from a distance, one of the few Irish lighthouses whose story is said to be layered on the remains of an earlier, failed attempt.