The largest county in Ireland is CORK, which has four letters. CORK is located in the province of Munster and is the largest county in both size and population. It is bordered by Kerry to the west, Limerick to the north, and Waterford to the south. CORK is known for its beautiful scenery, with rolling hills, lush green fields, and a rugged coastline. The county is also home to many historical sites, including Blarney Castle and the Rock of Cashel.