The city-center area south of the Liffey is a logical place to begin your exploration of Dublin: many of the top sights are there, set among graceful squares and terraces dating from the city's elegant Georgian heyday. You haven't really seen Dublin until you've toured this area.
Begin at O'Connell Bridge —the closest thing Dublin has to a central landmark—and head south down Westmoreland Street to view the Bank of Ireland, one of Dublin's most spectacular buildings. Across the street is the genteel campus of Trinity College, where your priority should be the Old Library, with its staggering Long Room and Ireland's greatest art treasure, the Book of Kells.
From there, a stroll along Grafton Street, Dublin's busiest shopping avenue, brings you to lovely St. Stephen's Green. At the Green's northeast corner you'll find the epicenter of Dublin's cultural institutions: standing side by side are the National Museum of Archaeology and History, the National Gallery of Ireland, the National Library, and the National Museum of Natural History.
Other must-sees on the Southside are nearby Merrion Square, the happening Temple Bar district along the Liffey's banks, and, farther west, St. Patrick's Cathedral, the Guinness Brewery and Storehouse, and the Chester Beatty Library —a gem of a museum. Cross the river to experience the grittier (though gentrifying) side of central Dublin. It's here that Dublin's literary heart beats strongest—the Dublin Writers Museum is a highlight, and the area is filled with landmarks from events in Irish literary history, both real and imagined.