Letterkenny is the largest town in County Donegal, Ireland. The town is located on the River Swilly. Letterkenny, located in East Donegal, and the nearby city of Derry, form the major economic core of northwest Ireland. In 2011, Letterkenny was named as the tidiest town in County Donegal, receiving 306 points, only four points behind the overall national winner, which was Killarney in County Kerry. It received a total of 47/50 points in the landscaping category and this was the highest number of points scored of any town in this category.