Baily Lighthouse, Howth, Co. Dublin

It is not a tall, slender thing in the way some lighthouses are; it rises in two distinct stages of dressed ashlar granite, blunt and solid, topped with a metal-framed glazed lantern that still catches the light long before the tower itself comes into view. The effect is less of elegance than of permanence, a structure built to withstand what the headland throws at it rather than to please the eye.

The lighthouse dates to 1814, a period when the approaches to Dublin Bay were becoming increasingly busy with shipping and increasingly dangerous without reliable marks. Around 1860, a five-bay, three-storey block was added to the north-west, presumably to house keepers and their families closer to the light they tended, and single- and two-storey coastguard buildings were built on the site to support the wider watch kept along this stretch of coast. For most of its working life the Baily depended on people, keepers living in shifts, trimming lamps, watching weather, until 1996, when the light was automated and the human presence that had defined it for over 180 years came to an end.

Little of that domestic life remains visible from outside the perimeter, but the cluster of buildings, the tower with its later addition, the coastguard structures nearby, gives a sense of a working station rather than a single monument. It is a place that rewards knowing what you are looking at: the change in stonework where the older tower meets the Victorian block, the practical scale of the coastguard buildings, the lantern itself still doing the job it was built for, now without anyone inside to trim it.