Gap of the North

The Moyry Pass is a geographical feature in Ireland. It is a mountain pass running through the Slieve Gullion between Newry and Dundalk. It is also known as the Gap of the North.

The pass was of historical military importance as it controlled the route between Ulster and The Pale around Dublin. Moyry Castle was constructed to guard the pass. A number of battles have been fought in or around the pass including the Battle of Moyry Pass in 1600 and several engagements during the Williamite War in Ireland.

...
Wikipedia