All of the searches listed are in repositories in Dublin City where Records Ireland is based.  They include:

National Archives of Ireland, Bishop Street, Dublin 8

Census of 1901 and 1911 for the entire country, Griffith's Primary Valuation, Tithe Applotment Books, Wills and Administrations, Surviving pre-1900 census records and transcripts, some Church of Ireland Parish registers, National School records, some Workhouse records, files of trials, inquest files, Prison records, and more.

National Library of Ireland, Kildare Street, Dublin 2

Roman Catholic parish registers of Baptisms, Marriages and Burials, Registers of Electors, Griffith's Primary Valuation of Ireland, Tithe Applotment Books, Estate Papers, Newspapers, Reference Material, Printed Books, Pedigrees and other Manuscripts, Directories, maps and more. 

General Register Office Research Room, 3rd Floor, Block 7, Irish Life Buildings, Abbey Street, Dublin 1

Civil Births, Marriages and Deaths from 1864 (non-Catholic marriages from 1845) for the entire country up to 1921 and for the Republic of Ireland from 1922-1995.  Adopted Children's Register.

Dublin City Library and Archives, 138-144 Pearse Street, Dublin 2

Some civil Indeces of Births, Marriages and Deaths, Directories, database of some Dublin Roman Catholic and Church of Ireland parish registers of Baptisms, Marriages and Burials, database of Dublin Electoral Registers, Newspapers and more.   

Registry of Deeds, King’s Inns, Henrietta Street, Dublin 1 

Memorials and Transcripts of Deeds relating to marriage settlements, wills, leases, sales and mortgages from 1708.