Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. County Mayo Irish: Contae Mhaigh Eo is one of the traditional counties of Ireland and is located within the province of Connacht. It was named after the village of Mayo, but the county seat is Castlebar. Mayo is the third largest of Ireland s 32 counties in area and 15th largest in terms of population. It is the second largest of Connacht s five counties in both size and population. The highest point in Mayo and Connacht is Mweelrea (814 m/2,671 ft). The river Moy in the northeast of the county is renowned for its salmon fishing. Ireland''s largest island, Achill, lies off Mayo''s west coast. Mayo has Ireland''s highest cliffs third highest in Europe at Croaghaun, Achill island.