Locally chosen, not algorithmic. In rough order of "if you only do one thing".
View
Croagh Patrick
A near-perfect quartzite cone on the south shore of Clew Bay. The pilgrim path from Murrisk car park climbs 764m in 7km return — steep, scree-loose on the upper third, two to four hours up depending on fitness. Tens of thousands climb it on Reek Sunday (last Sunday of July). St Patrick's chapel stands on the summit.
Good to know · Park at the Murrisk visitor centre. Allow 4–6 hours. Proper boots only — the upper scree is treacherous in trainers. Don't attempt in cloud.
Town
The Mall and the Octagon
Wyatt's 1780s plan: the Carrowbeg river running down the centre with stone-walled lime trees on either bank, three bridges crossing it. The Octagon, an eight-sided plaza with St Patrick on a column, anchors the southern end; Bridge Street climbs north to the clock tower. Matt Molloy's pub on Bridge Street belongs to the Chieftains' flute player — sessions nightly.
Good to know · Pay-and-display along The Mall. Friday Country Market on the Mall.
History
Westport House and Estate
An 18th-century Georgian mansion designed by Richard Cassels and James Wyatt, built on the foundations of an O'Malley castle (the family of pirate queen Grace O'Malley). House interior, formal gardens, and a separate Pirate Adventure Park for kids. Set on Clew Bay just outside the town centre.
Good to know · House and gardens seasonal — check website. Adventure park separate ticket. Free walking access to grounds.
Drive
Great Western Greenway
Ireland's longest off-road trail at 42km — Westport to Newport to Mulranny to Achill Sound, on the bed of the closed 1937 Westport-Achill railway. Walked, cycled, run; bike hire in all four towns. Westport-to-Newport is the easiest section — flat, 11km, around an hour by bike.
Good to know · Bike rental from multiple operators on James Street, Westport. Free to use; no permit needed.
View
Clew Bay viewpoint at Murrisk
Clew Bay is famously said to contain 365 islands — one for every day of the year. The view from the National Famine Memorial at Murrisk (a haunting bronze coffin ship by John Behan) takes in the bay, the islands, and Croagh Patrick rising directly behind.
Good to know · Free parking at Murrisk visitor centre. Memorial across the road.
Town
Matt Molloy's
On Bridge Street. Matt Molloy of the Chieftains has owned the pub since 1989. Sessions every night in the back room — proper sessions, players from across the country drop in unannounced. Get there early.
Good to know · Sessions usually start around 9.30pm. No bookings. Standing room only most weekends.
History
Cong — The Quiet Man village
South of Westport on the Mayo–Galway border, between Lough Mask and Lough Corrib, sits Cong — where John Ford filmed The Quiet Man in 1951 with John Wayne and Maureen O'Hara. The village is essentially a film location frozen in time: Pat Cohan's Bar (a real pub now, painted as it was in the film), the Quiet Man cottage, the bronze of Wayne and O'Hara on the green, the small Quiet Man Museum. Ashford Castle next door — a 13th-century Norman pile turned five-star hotel — was Ford's base while filming. The 12th-century Augustinian abbey ruins down by the river are quietly the best thing in the village.
Good to know · About 45 minutes south of Westport. Free parking by the abbey. Quiet Man tours from the village in season. Ashford grounds open to non-residents for a small fee.