The Wall

North of Concord and south of Coös County is the White Mountain National Forest, home of Mount Washington and the presidential range, as well as where the Old Man of the Mountain once could be seen before collapsing. People sometimes call this "The Wall", as it separates the North Country from the southern parts of New Hamsphire. Any towns north of the White Mountains are said to be "north of the Wall", and anything south of there are often described as "south of the Wall".

This is likely a reference to Game of Thrones.

Mountain passes through the White Mountains are often called "notches". Thus "north of the notch" has the same meaning as "north of the wall". For a list, see List of mountain passes in New Hampshire and Notches of New Hampshire