Clew Bay

Clew Bay (Cuan Mó) is a large ocean bay on the Atlantic coast of County Mayo, Ireland. It is roughly rectangular and has more than a hundred small islands on its landward side; Ireland's best example of sunken drumlins. The larger Clare Island guards the entrance of the bay.

The bay is overlooked by Croagh Patrick to the south and the Nephin Beg Mountains to the north. From the southwest part of the bay eastwards are the settlements Louisburgh, Lecanvey, Murrisk, and Westport; north of Westport is Newport, and westwards from there lies Mulranny, gateway to Achill.

History
The bay was historically known in Irish as Cuan Mod ("harbour of Mod") or Modlind ("pool of Mod"), and was associated with the Fir Bolg. This later became Cuan Modha. Some writers claim that this name derives from Modh, one of the Tuatha Dé Danann. Another possibility is the Old Irish mod, moth, which meant "penis" or "man".

Another old name is Cuan Umhaill ("harbour of Umhaill"). It was rendered in English as "Bay of the Owly" and "Bay of the Owles." Other English names were the Bay of Borace, Horrus, and Baragh, all references to Burrishoole (Buiríos Umhaill). The name 'Clew Bay', of uncertain origin, first appears in a 1714 map; it may be derived from cliath, "hurdle".

Clew Bay was the heart of the Gaelic territory of Umhaill, ruled by the Uí Máille (O'Malleys). Umhaill's last and most famous ruler was Grace O'Malley (Gráinne Ní Mháille), nicknamed "the pirate queen". The O'Malleys had a fleet of ships and several castles around Clew Bay, including Carrickkildavnet Castle, Carrickahowley Castle and Granuaile's Castle.

During the Irish Civil War in July 1922, 400 Free State troops were landed at Clew Bay to take Westport and Castlebar from Anti-Treaty forces.

In 2024, the discovery of a submerged late Bronze Age fort from the depths of Clew Bay was announced by a team from Connemara and Mayo County Council.

Inishgort Lighthouse
Inishgort Lighthouse stands on the island of Inishgort, 5 km from Murrisk.

Fish farming in Clew Bay
In recent years there has been controversy over fish-farming in the bay. "The Organic Salmon Company" (now owned by Mowi) is based in Clare Island.

Islands of Clew Bay
The bay is also home to Dorinish, a private island purchased by John Lennon in 1967. Glenans Ireland, a non-profit sailing school, had a branch on Collanmore Island where sailing was taught.

Legend has it that Clew Bay has 365 islands in it—"an island for every day of the year". The large number of drumlins at the east end of the bay gave rise to this myth, but in fact there are not so many.

Drumlin islands, sandbars, and rocks
This chart shows the relative positions of the islands, sandbars, and rocks in the eastern half of Clew Bay. There are 141 named islands and islets within the bay.