Slieve League, sometimes Slieve Leag or Slieve Liag (Irish: Sliabh Liag), is a mountain on the Atlantic coast of County Donegal, Republic of Ireland. At 601 metres (1,972 ft), it has Ireland's highest sea cliffs. Although less famous than the Cliffs of Moher in County Clare, Slieve League's cliffs reach almost three times higher.
The Belfast naturalist Robert Lloyd Praeger wrote in 1939:
A tall mountain of nearly 2000 feet, precipitous on its northern side, has been devoured by the sea till the southern face forms a precipice likewise, descending on this side right into the Atlantic from the long knife-edge which forms the summit. The traverse of this ridge, the "One Man's Path", is one of the most remarkable walks to be found in Ireland - not actually dangerous, but needing a good head and careful progress on a stormy day....The northern precipice, which drops 1500 feet into the coomb surrounding the Little Lough Agh, harbours the majority of the alpine plants of Slieve League, the most varied group of alpines to be found anywhere in Donegal.