CELTIC CHARM: Wicklow Mountains National Park, about an hour outside of Dublin.
Pete Ryan/National Geographic Stock
It’s a brilliant, cloudless day when I meet my first expert Dubliner. The city is in the midst of an unusually sunny and warm stretch — so unusual I’ve even heard reports of people being hospitalized for severe sunburns and heatstroke. The high temperature during my five-night stay: 68 degrees.

THE PLUCK OF THE IRISH: Dublin authority Pat Liddy
Railway Procurement Agency
Braving this “heat wave” in a checkered blazer, Pat Liddy, a 69-year-old former marketing executive and newspaper columnist who is considered the foremost authority on all things Dublin and who runs his own walking-tour company, meets me in the lobby of the Westbury Hotel, where I’m staying. We take off for Grafton Street, a tony and touristy pedestrian lane that is Dublin’s main shopping drag. “You must have coffee in Bewley’s and see the stained glass on the second floor,” says Liddy, pointing to a two-level coffee shop with a narrow balcony that has been here since 1927. Minutes later, we arrive in St. Stephens Green, where a sculpture memorializes The Great Irish Famine of the mid-1800s that killed more than 1 million people and prompted another million to leave the country.

“Are you of Irish descent?” Liddy asks, repeating a question I’ve heard several times since arriving in Dublin. When I explain my Sicilian-Irish heritage he says, “That’s … unique,” then launches into a discussion of how, around 1900, some Sicilian immigrants took over organized-crime networks that had earlier been established in the U.S. by some Irish immigrants. I could ask if this is an implication that I’m a criminal, or I could say nothing. I choose the latter, mostly because I’m not a talker. But Dubliners are. Roddy Doyle, a Dublin author, recently put it this way: “Dublin is not a place. Dublin is a sound … the sound of people who love talking, people who love words, who love taking words and playing with them, twisting and bending them … .”

Whether that chatter is the cause or the effect of the city’s great literary tradition, I don’t know, but Dublin boasts four Nobel Prize winners for literature. James Joyce, author of Ulysses and Finnegans Wake, wasn’t among them, but he is celebrated here. So Liddy takes me to Sweny’s, a former apothecary that opened for business in 1847 and that Joyce wrote about in Ulysses. Volunteers now run Sweny’s as a reading room for Joyce devotees.

We walk on to Trinity College Dublin, a school founded in 1592 by Queen Elizabeth I. There, facing the busy traffic on Dame Street, Liddy points out several “must-see” sites in every direction, each of which touches on a different part of a 1,200-year stretch of Dublin’s history, from the Viking settlements in the year 800 to the Irish War of Independence that ended in 1921. “I’ve been spending the better part of the past three decades trying to convince people to spend three or four nights in Dublin so they can see these sites,” Liddy says. “Some of the most significant events in the history of all Ireland happened right here on the streets of Dublin.”