Letterkenny , known as the
Cathedral Town, is the largest and most populous urban settlement in
County Donegal. Its English name is derived from the Irish name
Leitir Ceanainn, meaning "Hillside of the O'Cannons" – the O'Cannons being the last of the ancient chieftains of
Tír Conaill. With a population of 19,588, Letterkenny is located on the
River Swilly in east Donegal. Along with the nearby city of
Derry, Letterkenny forms the major economic core of the north-west of the
island of Ireland.