County Mayo (Irish: Contae Mhaigh Eo, meaning County of Plain of the Yew trees after Mayo Abbey) is a county in the province of Connacht, located on the west coast of Ireland. The county town of Mayo is Castlebar. Mayo is bordered to the south by Galway, to the east by Roscommon, and to the north-east by Sligo. Castlebar and Ballina are by far the two most populous towns in the county, with 10,729 and 10,146 residents respectively according to the 2006 census; with Castlebar being much larger by land area. These are followed by Westport, a popular tourist town, which has 5,140 residents. The fourth largest town is Claremorris with a population of 3,170. Other towns include Ballinrobe, Ballyhaunis, Belmullet and Swinford.

source: Wikipedia County Mayo