The road northwards from Donegal Town through Barnesmore Gap in the Bluestack mountains is one of the great scenic routes in Ireland.
Bearnas Mor, the "Big Gap" was created by a glacier, which carved a wide, deep valley in the mountain range. This highway has always been of strategic importance as a geographic link between the north and south of the county.
"The Gap", as it is known locally, has associations with St Patrick, who travelled across it on his first missionary journey through Connaught and Ulster. He had gone as far as Convoy, when, according to tradition, the wheel of his chariot broke twice. This event led the saint to conclude that it was a sign that his ministrations were unnecessary, predicting that the illustrious St. Colmcille would be born from the lineage of the ruling family, the Conall Gulban.