If you’re coming to Ireland to research your roots, this library should be one of your first stops, with thousands of volumes and records that yield ancestral information. Open at this location since 1890, this is also the principal library of Irish studies, particularly noted for its collection of first editions and the papers of Irish writers and political figures, such as W. B. Yeats, Daniel O’Connell, and Patrick Pearse. Parts of the collection are always on display to the general public (the exhibition devoted to Yeats is particularly good). The library also has an unrivaled collection of maps of Ireland. A specialist Genealogy Advisory Service is open Monday to Friday, 9:30am to 4:45pm. It’s free of charge; no appointment necessary.