As a proud native of Ramelton, Co Donegal I choose to believe that the song "The Maid of the Sweet Brown Knowe" refers to the Brown Knowe on the Ramelton/Rathmullan Road.   The Foot of the Sweet Brown Knowe" is
the left turn or elbow on the road to Ramelton at the bottom of the hill, known locally as the Brown Knowe.