The largest lake in the Republic of Ireland (and the second-largest on the island of Ireland), and arguably the finest wild brown trout water in Western Europe — 44,000 acres of limestone-enriched water split between Upper and Lower Corrib by the narrows at Knockferry. Upper Corrib (from Oughterard west) fishes 7–10 days earlier than Lower; its shallow, island-studded bays produce superb duckfly from March, then the legendary mayfly from mid-May — dapping with live mayfly is the traditional method and still the most magical. Lower Corrib fishes later, holds the lough's largest average trout, and favours olives, sedges, and dapped daddy longlegs through summer. Ferox trout to double figures are taken by trollers each season. A guide who knows how to handle the boat and where to look for fish is worth every penny — the vast lough has moods and hazards that locals know. Access is excellent: Oughterard (the best-known centre), Cong, Cornamona, Headford, Knockferry, and Annaghdown all have piers and boat hire. Season: trout opens 15 February, salmon 1 February, both close 30 September. A 12-inch size limit applies.
Named among the western limestone loughs for duckfly from around 17 March for about three weeks, followed by lake olives from late April to early May and a mayfly period running from after the first week of May into early June - regional guidance rather than a measured hatch on Corrib itself. The same source places Caenis at first light and sedges late in the evening through the summer months.
- Lough system
- Limestone








