Most of what follows sits in or around Clew Bay, the drumlin-filled bay between Westport and Louisburgh that holds 365 islands of its own. Clare Island guards the mouth of it, with Grace O’Malley’s abbey and its medieval wall paintings, and Knockmore rising 462 m straight out of the water. Collanmore, a 700-acre private-hire island reached by rib from Rosmoney Pier, and Dorinish, the 19-acre drumlin John Lennon bought in 1967, are both inside the bay. Ferries for Clare Island and Inishturk leave from Roonagh Pier, at the end of a long road west of Louisburgh.
The rest are north and west. Achill, the largest island in the country, you drive onto over the Michael Davitt Bridge, crossing the Curraun Peninsula to get there. Achillbeg lies off its southern tip, emptied of people in 1965; Inishbiggle sits in the Bullsmouth Channel between Achill and the mainland, eight residents and a weather-dependent crossing. Further north, Blackrock stands off the Mullet Peninsula, unlandable, watched from the shore. Bartra, off Killala, is the one you can walk to at low tide.
Timing matters more than distance here. Roonagh sailings are frequent through the summer and reduced, weather permitting, in winter, so a walk like Knockmore is planned around the fixed return time rather than the climb.
Ireland's largest offshore island, reached by bridge, holding the country's highest sea cliffs at Croaghaun, five Blue Flag beaches and a working Gaeltacht.
Sits at the mouth of Clew Bay, under twenty minutes from Roonagh Pier, with Grace O'Malley's abbey and its rare medieval wall paintings.
A near-vertical Atlantic rock off the Mullet, lit since 1864 and uninhabited since 1974; you cannot land, so it is viewed from shore.
Three hundred and sixty-five drumlin islands under Croagh Patrick, sailed for the seals, cycled on the Great Western Greenway or walked as an archaeological trail.
A 700-acre private-hire island twelve minutes by rib from Rosmoney Pier, with a white-sand beach and water sports, but only for booked groups.
17 of 18 shown — tap a pin for the place.
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Achill is Ireland's largest offshore island, 36,500 acres off County Mayo, joined to the mainland by the Michael Davitt Bridge and anchoring this stretch of the Wild Atlantic Way. It holds the country's highest sea cliffs at Croaghaun (688 m), five Blue Flag beaches, a famine-era deserted village and a population of around 2,300 who keep the Gaeltacht alive.
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Clare Island sits at the mouth of Clew Bay, the ancestral seat of the pirate queen Grace O'Malley. Its 15th-century abbey holds the most complete set of medieval wall paintings in any Irish church, its old lighthouse is now a guesthouse, and a short ferry from Roonagh Pier gets you there in under twenty minutes.
Belmullet, mayo
Blackrock is a near-vertical Atlantic rock off the Mullet Peninsula, topped since 1864 by one of Ireland's most remote lighthouses. No one has lived there since it was automated in 1974, and the public can't land, so you view it from the Mullet or Achill, where it stands on the horizon like a volcano. Its keepers' history takes in a man lost to a freak wave, a 1940 air attack and a months-long wartime siege.
Westport, mayo
Clew Bay holds 365 drumlin islands left by the Ice Age, with Croagh Patrick to the south and Grace O'Malley's tower houses on the shore. You can sail it for the seals, cycle the 42 km Great Western Greenway along its north side, or walk a 21-site archaeological trail from Westport to Clare Island.
Clew Bay, mayo
Collanmore was once the Irish base of the Les Glénans sailing school; today the 700-acre island is a private-hire lodge in Clew Bay. A 12-minute rib transfer from Rosmoney Pier brings groups to a white-sand beach, guided water sports and a full view of Croagh Patrick. There is one catch: you cannot visit without a booking.
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The Curraun Peninsula is the Gaeltacht headland you cross to reach Achill Island, and it is almost an island itself, tied to the mainland by a land bridge just 800 metres wide. Corraun Hill dominates it, the Great Western Greenway runs along its north shore, and the Atlantic around it is some of the best sea angling in Ireland.
Clew Bay, mayo
Dorinish is a 19-acre uninhabited drumlin island in Clew Bay that John Lennon bought at auction in 1967 and later handed to a short-lived hippie commune. There are no facilities and no ferry, so you either arrange a boat from one of the local piers or get the panorama from a Clew Bay cruise. The reward is the view: Clare Island, Croagh Patrick and the Nephins all at once.
Ballycroy, mayo
Eight people live on Inishbiggle, a 2.6 km² island wedged in the Bullsmouth Channel between Achill and the Mayo mainland. It's an unusual place – both a Gaeltacht and a traditionally Protestant community – reached only by a short, weather-dependent ferry. There's a coastal loop walk, a Protestant chapel and very little else, which is the point.
Inishturk, mayo
Inhabited on and off for 6,000 years, Inishturk is a 5km-by-2.5km Atlantic island off Mayo with a permanent community of 56. Wall-like north-west cliffs, a ruined Napoleonic signal tower, two looped walks and a rare sea lagoon at Portdoon reward the hour-long ferry from Roonagh Pier.
Clare Island, mayo
Knockmore is the 462 m high point of Clare Island, rising straight out of the Atlantic off the Mayo coast. It's a non-technical hill walk on heather and peat, with Clew Bay and its drowned drumlins spread out below – but the ferry, with its fixed return times, is the part that needs planning, not the climb.
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Lough Mask spreads over 22,000 acres of limestone water on the Mayo–Galway border – the fourth-largest lake in the Republic and one of its great wild brown-trout fisheries. Shallow, island-strewn eastern bays give way to deep western channels dropping to 58 metres. Cong, Ballintubber Abbey and the Lough Mask Distillery are all within easy reach.
Roonagh Quay, mayo
Roonagh Pier is the departure point for ferries to Clare Island and Inishturk, at the end of a long road west of Louisburgh. It's a working pier rather than a sight in its own right, but the view while you wait takes in Croagh Patrick, Mweelrea and the Achill cliffs. Sailings are frequent in summer and reduced, weather-permitting, through the winter.
Achillbeg, mayo
Killala, mayo
Belmullet, mayo
Mullet Peninsula, mayo
Belmullet, mayo
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