Connemara ( ) is a district in the west of Ireland, the boundaries of which are not well defined. Some define it to be the land contained by Killary Harbour, the Maam Valley, Lough Corrib (as far as Moycullen); a line from there to the sea at Barna and the Atlantic Ocean. The historical territory of Connemara, as defined by the 17th century historian Ruaidhrí Ó Flaithbheartaigh in his book West or H-Iar Connaught, was coextensive with the barony of Ballynahinch, This is a broad peninsula stretching from Killary Harbour on the north to Kilkieran Bay on the south. The boundary runs from the north along the spine of the Maumturk Mountains then along a series of small rivers and across upland west of Maam Cross eventually following the course of the Invermore river before meeting the sea west of the Ros Muc peninsula.