Tearaght's longitude is 10 degrees 39.7 minutes west, just slightly farther west than Inishvickillane and considerably west of Iceland's eastern shore. A few exposed rocks lie even farther out - Tearaght Rocks at 10 degrees 41, Foze Rocks at 10 degrees 41.3 - but they are tide-washed pinnacles where landing is impossible. Tearaght proper is the last real land. The island is roughly a kilometre east-to-west and 500 metres north-to-south, split into two parts: a larger eastern summit rising to 254 metres, and a smaller western one topping out at 116. A narrow neck of rock joins them, pierced by a natural tunnel through which the Atlantic surges in heavy weather. The Wikipedia traveller's habit of treating Tearaght as a footnote to the Blaskets misses what makes it geographically extraordinary: it is the edge of the European land mass.

In 1870, the Commissioners of Irish Lights commissioned and lit the Inishtearaght Lighthouse on the western summit of the island. The decision was driven by the brutal navigational mathematics of the late nineteenth century - too many ships heading for Liverpool, Belfast, or Cork were running onto the Kerry reefs in fog. The structure that resulted is small, square, and white, set on a rock face that drops vertically into deep water. Materials had to be hauled up from the boat landing by funicular railway, a near-vertical track up the cliff that still survives in ruined form. Keepers and their families lived in a row of small cottages near the light, supplied irregularly from the mainland and rotated through the station on a schedule that depended entirely on the weather. From 1913 onward, the station was operated continuously. In 1988, after 118 years of human residence, the lamp was automated and the last keepers left.

Without keepers, the island became a seabird metropolis. Tearaght holds internationally important populations of Manx shearwaters and European storm-petrels - the same nocturnal, burrow-nesting species that animate the rest of the Blaskets, but here in unusual abundance for the limited area. Leach's storm-petrels have been recorded in recent years, though breeding has not yet been confirmed. The auk colonies - especially the puffins on the lower slopes - have fluctuated considerably across the decades, in ways that early counters could not reliably document. What is documented is the noise. To approach Tearaght by boat on a summer evening is to enter a wall of seabird sound: the cackle of guillemots, the moan of fulmars, the strange dry click of shearwaters wheeling at altitude before slipping down to their burrows at full dark.

The keepers who lived here for over a century left almost no romance behind in writing. The Commissioners of Irish Lights operated their stations on a strict bureaucratic logic; the keepers were professional civil servants and their letters home tend toward weather, supplies, and the next leave. What we know about life on Tearaght comes mostly from inference: from the rain channels carved into the rock to collect drinking water; from the foundations of small terraced gardens where keepers grew what they could; from the funicular's rusting cable; from the photographs taken in 1987, just before automation, that show small whitewashed cottages with their doors painted shut against the wind. The keepers stood watches. The lamp burned. The fog signal sounded. Nothing about it would have been comfortable. And yet for 118 winters, someone climbed the path each evening to start the light.

Today the lamp on Tearaght still flashes - white, every twenty seconds, visible for nineteen nautical miles - but no human attends it. The light is monitored remotely from Dublin and serviced by helicopter when something fails. The cottages are sealed. Visitors arrive rarely, mostly seabird researchers and a handful of intrepid kayakers who time their crossings to a flat sea. Tearaght has become what the older Blaskets became fifty years before it - a place where humans no longer live but whose stone marks still stand. The difference is the lamp. Every evening, in fog or in summer twilight, the most westerly fixed light in Europe still goes on. The Atlantic, indifferent, continues to flow through the natural tunnel below it, and the storm-petrels return to their crevices to feed their young in the dark.