Presenter Joe Mahon visits Arranmore Island off the north west coast of County Donegal. Dr Kevin Quinn, the local GP, walks along the beach with Joe and tells him about one of his predecessors as island doctor who looked after typhoid victims in the late 19th Century before succumbing himself. Jerry Early tells Joe how his family emigrated to the US but returned to Arranmore when he was a small child. Andrew Early then recalls how salmon fishing began on the island and how the tradition has died.

In a ruined lightboat station, Joe finds a memorial to those lost at sea and then recounts the harrowing story of the Arranmore Disaster when nineteen lives were lost including thirteen from the Gallagher family. Annie Bonner tells Joe about the setting up of the first ferry service to the island and how it changed life for the islanders.

Nora Flanagan shows Joe a hanging patchwork quilt made by a women's group on the island and explains the story of the images decorated on it. Connie McCauley walks with Joe telling him about the difficulties of delivering the mail on an island where so many people have the same name. Joe visits the Atlantic coast side of the island to speak to Charlie Boyle about his work as the lighthouse attendant.

Lesser Spotted Ulster is a long-running and popular programme that visits the places many of us have heard of but never been to. Presenter Joe Mahon gently explores what makes a place what it is.