Clew Bay – 365 islands and a pirate queen

Overview

Clew Bay (Irish: Cuan Mó) is studded with islands – local tradition counts 365, one for every day of the year. They are drumlins, low mounds of glacial debris left when the last Ice Age retreated and the sea flooded in around them, which is why so many sit half-drowned with their tails trailing into the water. The bay runs roughly 16 km east to west and 11 km north to south, on County Mayo’s Atlantic coast. Croagh Patrick rises on the south shore, the Nephin Beg range on the north. The largest island, Clare Island, sits across the mouth; smaller ones include Dorinish, which John Lennon bought in 1967, and Collanmore.

If you only have time for one thing, take a boat out – the islands only make sense from the water, and that is where the seals are.

History

In medieval times the bay was the heart of the Gaelic lordship of Umhaill, held by the O’Malley (Uí Máille) clan. The 16th-century sea captain and chieftain Grace O’Malley worked these waters, and two of her tower houses still stand on the shore: Rockfleet (Carraig an Chabhlaigh), near Newport, and Carrickkildavnet on Achill. The O’Malley motto, Terra Marique Potens (‘powerful by land and sea’), fits a family that lived by both.

A submerged late Bronze-Age fort, found in the bay in 2024, shows how long this coast has mattered. Much later, in July 1922, 400 Free State troops landed here during the Civil War to take Westport and Castlebar.

Older still are the stone monuments scattered around the shore. The Boheh Stone near Westport carries cup-and-ring carvings, and twice a year – on 18 April and 24 August – the setting sun appears to roll down the northern slope of Croagh Patrick from where the stone stands, an alignment identified by local archaeologist Gerry Bracken. Add the Srahwee wedge tomb near Louisburgh (c. 3000–2000 BC), the 12th-century doorway at Oughavale Churchyard, and the 1997 National Famine Monument at Murrisk, and you have most of Irish history within a short drive of the same bay.

Wildlife

A colony of around 400 harbour seals lives in the sheltered water, and most boat tours will get you close to them. Dolphins turn up but can’t be counted on. The cliffs and outer islands hold nesting guillemots and razorbills, with the odd puffin in summer. Bring binoculars; from a moving boat you’ll want them.

Boat tours

• Westport Cruises – 90-minute sailings from Westport Quay, daily from 1 May to 31 October. The boat has a heated lounge, a bar, a café and accessible toilets, and the route passes the seal colony.
• Clew Bay Charters (Newport) – April to October, on a fully accessible catamaran. Choose the two-hour sightseeing run among the islands or a half-day’s angling.
• Ferries – regular sailings link Roonagh Quay (west of Louisburgh) with Clare Island and Inishturk, and there are services to Achill.

Croagh Patrick and Murrisk

Croagh Patrick – the ‘Reek’ – is 764 m and stands over the south shore. The usual route up from Murrisk is about 7 km return and takes most people 3½ to 4 hours. The reward is the bay laid out below with its islands, Clare Island beyond, and the open Atlantic. Be honest with yourself about it: the upper section is a slog of loose scree that’s hard on the knees coming down, and the summit clouds over often. Pick a clear day, wear proper boots, and don’t bother if the cloud is already sitting on the cone – you’ll see nothing from the top.

At the foot of the mountain, Murrisk has a car park, the 15th-century Murrisk Abbey linked to the O’Malleys, and the National Famine Monument, a bronze coffin ship by John Behan.

Cycling the Great Western Greenway

The Great Western Greenway is a 42 km traffic-free trail along the old Westport–Achill railway, following the north side of the bay. It splits into three moderate sections:

1. Westport to Newport (12 km)
2. Newport to Mulranny (18 km)
3. Mulranny to Achill (14 km)

Clew Bay Bike Hire rents Giant road, electric and family bikes, with a free shuttle between its bases in Newport, Mulranny and Achill – useful if you only want to ride one way. The longer Clew Bay Bike Trail loops 105 km on coastal roads and inland tracks for those with the legs for it.

The archaeological trail

The Clew Bay Archaeological Trail is a self-guided route of 21 marked sites in four stages, taking in Westport, Murrisk, Louisburgh and Clare Island. Each site has a brown information panel, but they can be hard to find on rural roads, so bring a GPS or a phone map. A few of the better stops:

You can do the mainland stages in a day, but Clare Island means a ferry from Roonagh, so treat the island sites as a separate trip. The Clare Island Abbey wall paintings are the standout of the whole trail.

Getting there

Westport sits on the N5 and is served by Bus Éireann from Dublin, Galway and Castlebar. The nearest airport is Ireland West Airport Knock, about 45 km away. A car helps a great deal for the trail’s rural sites; public buses cover the main towns of Westport, Newport, Mulranny and Achill but not much in between.

For parking, Westport Quay has short-stay spaces (fees apply), Murrisk has a free car park, and the Clare Island ferry terminals have limited parking.

Practical notes

• Boat season: tours run May to October. The Greenway and most walks are open year-round, though winter brings wind, rain and short days.
• Accessibility: Westport Cruises and the Clew Bay Charters catamaran take wheelchair users, and the Greenway is largely level. Many of the old monuments sit on rough, uneven ground.
• What to bring: walking boots, a waterproof, binoculars, and a charged phone or GPS for the trail.
• Safety: tides run hard around the islands – take local advice before kayaking or swimming, and keep your distance from the protected seal colonies.

Nearby

• Achill Island – reached by road at the end of the Greenway, with cliffs, beaches and Kildavnet Castle.
• Ballycroy National Park – north of the bay, in the Wild Nephin mountains, with long walking trails.
• Westport – the obvious base, with the boats leaving from the quay and Westport House on the edge of town.