This site generates income via partnerships with carefully selected travel brands and/ or purchases made through links to them. As an Amazon Associate I earn from qualifying purchases. See why this is important.Exquisitely created to house a fragment of the True Cross in 1123, this shrine was kept in the Augustinian Friary at Cong, County Mayo, for centuries. A mix of early Celtic style decoration and Viking styles of the 11th and 12th century, the Cross of Cong is just one of the treasures at the National Museum of Archaeology in Dublin.