Cathair na Mart · Co. Mayo
A planned Georgian town under a holy mountain. Yes, those go together.
Westport is the rare Irish town that was drawn before it was built. James Wyatt set out the Mall along the Carrowbeg river in 1780, put stone bridges across at regular intervals, dropped an octagon in the middle, and let the Browne family pay for it from their seat at Westport House. Two and a half centuries later you can still walk the plan in fifteen minutes and feel how thought-through the whole thing is.
What you need to know: it does several jobs at once. It's a market town for South Mayo, a base camp for Croagh Patrick pilgrims, the trailhead for the Great Western Greenway out to Achill, and a working pharma town - AbbVie employs more than a thousand people up the road. The pubs absorb all of that. On any given Saturday night Matt Molloy's will have a fluter from the Chieftains, two American couples mid-greenway, three lads in high-vis off shift, and a pilgrim still in the boots she climbed in.
Don't try to do it as a day-trip. The town runs on its evenings. Climb the Reek if the cloud lifts, ride the greenway as far as Newport for lunch, eat a proper dinner at An Port Mór, and roll into a session that's been going since you were drying your boots. Stay two nights and you'll start to understand why the Brownes never sold up.