Slieve League is a mountain on the Atlantic coast of Ireland. It is one of Europe's hidden gems. The cliffs at Slieve League (or "Sliabh Liag" in local Gaelige) are twice as high as the famous Cliffs of Moher. I consider it as one of the finest marine cliffs in Europe. You can hike the 'one man's pass' and can also see dolphins play on some days! Breathtaking.