A cornucopia of things quintessentially Dublin, this area is studded with treasures ranging from the opulent 18th-century salons of Dublin Castle to time-burnished St. Patrick's Cathedral, and from the Liberties neighborhood—redoubt of the city's best antiques stores—to the Irish Museum of Modern Art (housed at the strikingly renovated Royal Hospital Kilmainham). You can time-travel from the 10th-century crypt at Christ Church Cathedral—the city's oldest surviving structure—to the modern plant of the Guinness Brewery and its storehouse museum. You can also cross the Liffey for a visit to Smithfield, Dublin's old (but recently revitalized) market area where flowers, fruit, vegetables, and even horses have been sold for generations. Traditional-music bars sit side by side here with modern hotels and the newly refurbished Old Jameson Distillery museum.
Keep in mind that Dublin is compact. The following sights aren't far from those in the other city-center neighborhoods. In fact, City Hall is just across the street from Temple Bar, and Christ Church Cathedral is a short walk farther west. The westernmost sights covered here—notably the Royal Hospital and Kilmainham Gaol—are, however, at some distance, so if you're not an enthusiastic walker, you may want to drive or catch a cab, bus, or LUAS tram to them.