Touring western Ireland was a dream my wife and I shared when we married 14 years ago. Seasoned travelers, now in our 60s, we finally started planning last summer for a four-day jaunt to be tacked onto a business trip ending in Dublin.

That’s when we discovered that — like many vacationing couples — we had different agendas. We both wanted to see the countryside and wander through villages, but Eileen was also eager to visit newfound Irish relatives, while I had castles on my mind. And not just any castles: I envisioned tracking down the mysterious ruins pictured in “Irish Castle,” a serigraph by contemporary American artist Thomas McKnight that’s been a fixture on my living room wall since 1982.

How to satisfy both of our cravings? The answer turned out to be a private guide, one skilled in finding both castles and cousins.

Having your own chauffeur take you around may sound like a luxury. The person we lined up through Toursby­locals.com cost us about twice what we would have spent for bus tours taking us through the same towns and sites that we had wanted to include on our trip. (We rejected the idea of renting a car as too onerous.) But for us, the personalized approach added a huge amount of value to the trip. Indeed, we would happily recommend it as well worth the extra money.

Our preparation started six months before our planned departure with a search of a half-dozen Internet sites that link customers with local tour guides. Toursbylocals.com, based in Vancouver, B.C., appealed to us — especially after we found a profile of an Irish guide that made us smile. The guide, James Ryan, expressed interest in “genealogy detective work,” and he noted that the current U.S. president had come to Ireland in 2011 “to find the apostrophe in O’Bama.”

Travelers Roy Harris and wife Eileen McIntyre prepare to tour Kylemore Abbey, a 19th-century castle in the Connemara area. (Roy Harris)

In our e-mail exchanges, James said he also was intrigued by our quest for the mysterious castle. We signed up with him in August and sent in a deposit, based on his $420-a-day rate. He agreed to plan a route that included towns that interested us — Galway, Killarney and Limerick — along with exploration of the Connemara region and the Dingle Peninsula.

Having a personal guide online brings early benefits to travelers: inspiring curiosity about what you’ll be seeing and where you’ll be staying, for starters. James knew of several hotels at our “midrange” price target of $100 a night, and our preferred location near the center of town; when we mentioned bed-and-breakfasts, he warned us that many of the best ones are closed for the season in late November. For our part, the online process of researching and reserving rooms got us busy familiarizing ourselves with the trip ahead.

That familiarity paid off on Day 1 of our tour. Arriving at the Galway rail station from Dublin, we had only a short walk with our bags to the Park House Hotel, which also was a mere two blocks from the town’s Eyre Square. It turned out to be the day Galway’s Christmas festival was opening in the square.

We made connections for dinner that evening with two cousins Eileen had contacted in advance: Kitty Costelloe, a dairy farmer, and her daughter Amanda, a local teacher. Over pub food, they helped us choose a special seafood restaurant where the two of us would celebrate our anniversary the next night. They also arranged a meeting with another of Kitty’s children: policeman Paddy Costelloe, who lived closer to Shannon Airport, where our travels would end a few days later.

James, driving the 30 miles from his home town of Ennis early the next morning, had a full itinerary in Connemara ready for us. We started with a look at the area’s offering of distinctive green marble and then drove to the magnificent Kylemore Abbey, a relatively new castle (built in 1867) that also has seen duty as a Benedictine nunnery and a prestigious boarding school.

We passed several other castles, too, but none had the look — or the lakeside setting — of the one hanging in our living room back home in New England. Not to worry, our guide advised as he studied a photographic likeness of the McKnight “Irish Castle.” James had in mind a ruin that was just outside Killarney that might qualify on the third day of our tour.

The morning after our anniversary, James drove us south from the green expanses of County Galway into the starkly lunar landscape of the Burren, a stretch of exposed limestone where it has been said that “there is not water enough to drown a man, wood enough to hang one, nor earth enough to bury them.” Then it was on to the Cliffs of Moher, where our guide gave us ample time to explore this most spectacular conjoining of Irish shore and sea.

Thomas McKnight’s “Irish Castle” on the author’s living room wall. (Family photo; Serigraph: Copyright 1981 Thomas McKnight )

The next day, passing through the town of Tralee, we wound our way around Dingle’s charming coast and were treated to a mix of breathtaking ocean and pastoral panoramas. The off-and-on rain showers that greeted us proved fortunate when they brought vivid rainbows — and a set of remarkable photos.

After our third night, in Killarney, James took us first thing to Ross Castle, a 15th-century ruin on Lough Leane — a lake we had seen from a distance, among rolling hills that strikingly resembled the landscape in our “Irish Castle” serigraph. James smiled, seeing the look of recognition that he’d hoped Ross Castle would spark.

Mission accomplished, Eileen and I thought.

Then it was off toward the lovely thatched-roof houses of Adare, where James introduced us to a heraldry shop where we ordered some family-crest plaques to be shipped back home. In nearby Limerick we toured the enormous King John’s Castle, which for all its wonders bore no resemblance to “our castle.” Our final night was spent in Ennis, where we made our last family connection, with Paddy Costelloe. With Ennis being James’s town, we took seriously his recommendation of a pub with Irish music. The evening was a hit. And when it came time the next day for James to take us on the short ride to Shannon Airport, we flew home feeling we’d learned much about Ireland, its castles, our cousins — and our guide.

All three of us were amused, then, when I later was able to connect with artist Thomas McKnight and get the true backstory of our “Irish Castle” serigraph. In an e-mail response from his home in Connecticut, McKnight wrote that he had never been to Ireland, and “the image of the castle must have come from a book, although I don’t remember which one.” He added, “To me the position of the castle in a lake epitomized that Celtic land of myth and mystery. Perhaps it’s in my genes; I am part Irish, hence my surname.”

Eileen and I assured him that he had captured the landscape perfectly, and suggested he make the trip to Killarney some day.

We may just know a tour guide to show him around.

Harris, who lives in Hingham, Mass., is a former Wall Street Journal reporter and the author of “Pulitzer’s Gold: Behind the Prize for Public Service Journalism.”