Inishtrahull (, possibly "island of the empty beach" or "island of the yonder beach") is the most northerly island of Ireland. It has an area of and lies about northeast of Malin Head, County Donegal. The most northerly landfall of Ireland, the Tor Beg rock, is another kilometre to the north. Inishtrahull is home to Ireland's northernmost lighthouse. The island had a resident community until 1929 and the lighthouse was staffed until 1987. Today it is uninhabited and has been designated a protected area due to its wildlife. Geology The island is formed of a granitic gneiss, a type of metamorphic rock, which is known as Inishtrahull Gneiss. It is dated at 1.7 billion years old, making it Paleoproterozoic in age, and is the oldest known rock on the Irish Islands. The Inishtrahull Gneiss is considered to form part of the Rhinns complex that is also exposed on the islands of Islay and Colonsay. The Rhinns complex is correlated with the Ketilidian metamorphic belt of southern Greenland and the Svecofennian of Scandinavia. Biology Among the algae present at Inishtrahull, Bonnemaisonia asparagoides, Callophyllis laciniata, Kalymenia reniformis, Sphaerococcus coronopifolius, Lomentaria articulate, L. orcadensis, Rhodymenia pseudopalmata, Plumaria plumose, Ceramium shuttleworthianum, Heterosiphonia plumose, Nitophyllum punctatum, Hypoglossum hypoglossoides, Drachiella spectabilis, Odonthalia dentate, Osmundea pinnatifida, Polysiphonia lanosa, P. stricta, Enteromorpha intestinalis, Ulva lactuca, Fucus serratus, F. spiralis and Ascophyllum nodosum have been recorded. Population and history The island is now uninhabited but had a resident community until 1929 and lighthouse keepers until 1987. The evacuation of the community from Inistrahull took place en bloc in 1929. The matter was raised in a Dáil debate on illegal fishing in November 1929 by the TD for the area, Deputy Frank Carney. The Deputy stated that Inishtrahull was one of the few places in the country where the population had actually increased by almost 100% from 1881 to 1901. He said that the people on the island had a school and a graveyard and earned their livelihood from the fishing industry with very small boats for inshore fishing and that they could line fish and fish with nets during the herring season. Deputy Carney said that, ordinarily, they were able to make a reasonable living. However, he said that because of illegal fishing by "Scotch and English trawlers and French fishing smacks" the islanders had been compelled some weeks earlier to evacuate the island, desert their homes and leave