The Leg O' Mutton Lake can be found on the Castlebar to Newport road in Co Mayo, it is situated on a loop of road that enters and exits onto the main road.
Its claim to fame is that Princess Grace of Monaco's grandfather, John Bernard Kelly, was born in a two-roomed cottage overlooking the "Leg of Mutton" lake at Drimurla where he eked out a living before emigrating to the US in 1887.