Lough Conn is a celebrated 5,700-hectare limestone lake in County Mayo, stretching approximately 14 kilometres from north to south and up to six kilometres wide. Nestled between the Nephin Beg mountains and the River Moy catchment, it is a broad, wind-swept water body renowned as one of Ireland's premier wild brown trout fisheries. The lake reaches a maximum depth of 37.9 meters and is characterized by its shallow limestone bays and iron-marked shoals. It is part of the River Moy system, connected to Lough Cullin to the south and ultimately the Atlantic Ocean. The fishery is entirely free, with no permit required, and is celebrated for its naturally reproducing, unstocked fish populations, offering a genuinely remote angling experience.