Islandeady is a rural parish that doesn't perform for tourists. The name means "island of Éadach" — likely a saint or a settler — and the lake is real: Islandeady Lake lies to the west, Lough Lannagh to the south. The land around them is quiet farmland, stone walls, and houses set back from the road with long drives. There's a church, some sheep, a post office that closes at half one.
This is the country west of Castlebar before you drop into Croagh Patrick country. You come here to walk, or to visit family in a house you already know, or because you got lost on the way somewhere else and decided to stay an hour. That's fine. The lake is worth an hour.
Wear waterproofs. Bring a sandwich. Tell someone where you're going if it's the mountain.
There is no bad time. There are different times.
Lambing season, lambs actually visible, water high.
Dry ground, long evenings, midges still reasonable.
Storms, big skies, reeds starting to gold.
Muddy, short light, the quiet becomes serious.
From Castlebar, take the N5 west towards Croagh Patrick. Turn right (north) at the signpost for Islandeady. About 8km from the town centre, twenty minutes.
No direct bus. Castlebar is the hub; from there you'll need a taxi or a car.