Illanmaster or Illaunmaistir is an uninhabited steep rocky island rising to about 100m, lying just off the north coast of County Mayo

County Mayo

County Mayo is a county in Ireland. It is located in the West Region and is also part of the province of Connacht. It is named after the village of Mayo, which is now generally known as Mayo Abbey. Mayo County Council is the local authority for the county. The population of the county is 130,552...

, Ireland

Republic of Ireland

Ireland , described as the Republic of Ireland , is a sovereign state in Europe occupying approximately five-sixths of the island of the same name. Its capital is Dublin. Ireland, which had a population of 4.58 million in 2011, is a constitutional republic governed as a parliamentary democracy,...

 and 19km west of Ballycastle

Ballycastle, County Mayo

Ballycastle is a village in County Mayo, Ireland, situated northwest from Ballina, near Mayo's north coast in the West of Ireland. Ballycastle is also on the edge of an Irish speaking area called a Gaeltacht....

. Grid ref: F 933 435. The island is separated from the mainland by a narrow sound.

Wildlife

It has breeding puffins

Atlantic Puffin

The Atlantic Puffin is a seabird species in the auk family. It is a pelagic bird that feeds primarily by diving for fish, but also eats other sea creatures, such as squid and crustaceans. Its most obvious characteristic during the breeding season is its brightly coloured bill...

 and storm petrels

European Storm-petrel

The European Storm Petrel or Storm Petrel is a small bird of the storm-petrel family, Hydrobatidae, part of the seabird order Procellariiformes. It is the only member of the genus Hydrobates.-Description:...

, and in winter is used by a small flock of Barnacle Geese

Barnacle Goose

The Barnacle Goose belongs to the genus Branta of black geese, which contains species with largely black plumage, distinguishing them from the grey Anser species...

. The island is managed as a nature reserve

Nature reserve

A nature reserve is a protected area of importance for wildlife, flora, fauna or features of geological or other special interest, which is reserved and managed for conservation and to provide special opportunities for study or research...

 by BirdWatch Ireland

BirdWatch Ireland

BirdWatch Ireland is the current name of the organisation that used to be known as the Irish Wildbird Conservancy.BirdWatch Ireland is the leading voluntary conservation organisation in the Republic of Ireland, devoted to the conservation and protection of the Republic of Ireland's wild birds and...

. The reserve is inaccessible but can be viewed from the mainland.