County Mayo borders the Atlantic Ocean on the western coast of the Republic of Ireland. Ireland is divided into four provinces and Mayo is a part of the province of Connaught, the western province.
Castlebar is the county seat of government where the Mayo County Council is headquartered. Mayo's other two towns with Town Councils are Ballina and Westport.
It's 2002 population was 117,446 and growing. Mayo's total land area is 5585 km2. It's population density is approximately 19.9 inhabitants per kilometre.
Mayo has several significant mountain ranges which include three of the highest points in Ireland: Mweelrea (814 metres), Nephin (806 metres) and Croagh Patrick (764 metres).
Croagh Patrick is also the site of a major annual religious pilgrimage which commemorates St. Patrick's own religious experience on the mountain (it was from its summit that St. Patrick is said to have banished snakes from Ireland, and it was also here that he is said to have spent 40 days and nights in meditation, fasting and prayer). The annual pilgrimage sees thousands of the faithful climbing to the summit to complete a ritual of prayers and penance.
Mayo's other famous pilgrimage site is Knock. Knock was a small town until August 21st 1879, when two local women said they saw an apparition of Mary, Joseph and St John the Evangelist at the south gable of the parish church. Thirteen other local people came to the site following their report and confirmed the apparition. Since then, the town has become a major pilgrimage site for the pious and those seeking cures for physical ailments. The town includes a basilica as well as the original parish church and various chapels catering to the pilgrims.
Mayo is also home to the Céide Fields, a 5000 year old Neolithic farm stead. Visitors can tour an interactive museum which explains the significance of the site as well as walk the site itself, exploring its peoples' complex system of agriculture and way of life.
Mayo's most famous river, the Moy, is world famous among fishermen for its bounteous schools of Salmon, Trout, Pike and others.
Mayo has the longest coastline of any county in Ireland and sports a number of islands and bays. Mayo is home to Ireland's largest Island, Achill whose area is 148km2.