The bay on Ireland's west coast containing the Aran Islands at its mouth is Galway Bay. It lies between County Galway to the north and County Clare's Burren region to the south, with Galway city on its northeastern shore.
Galway Bay is about 50 kilometres long and between 10 and 30 kilometres wide. The River Corrib flows into it at Galway, while the bay opens westward toward the Atlantic through passages around the Aran Islands. Those three islands—Inishmore, Inishmaan and Inisheer—form a prominent natural gateway at the bay's mouth.
The islands are famous for limestone landscapes, stone walls, Irish-language communities and archaeological sites such as Dún Aonghasa. Their geology is closely related to the limestone of the Burren, while the northern side of Galway Bay is associated with the granite landscapes of Connemara.
Galway Bay is also strongly linked with maritime culture. The traditional Galway hooker, a distinctive sailing boat, was developed for local waters and coastal trade. A common mix-up is Donegal Bay, another large bay on Ireland's northwest coast; it does not contain the Aran Islands at Galway Bay's entrance.