The National Archives of Ireland is the official repository for the state records of Ireland.
Established by the National Archives Act 1986, taking over the functions of the State Paper Office (founded 1702) and the Public Record Office of Ireland (founded 1867). In 1991, the National Archives moved to its current premises in Bishop Street, Dublin.
They cite their mission statement as, "Securing the preservation of records relating to Ireland which warrant preservation as archives and ensure that appropriate arrangements are made for public access to archives."
They hold records relating to all of Ireland, including documents that refer to the Republic of Ireland and Northern Ireland; although Northern Ireland does have their own archives which is titled the Public Record Office of Northern Ireland (PRONI).
Image is a modification of an original image courtesy of Doyler79