For two centuries, Strancally Castle’s towers and parapets have overlooked a bend in the Blackwater River and a swath of Irish land as it passed from one wealthy family to the next.
It now joins the holdings of Mark Zuckerberg, one of the 21st century’s most prominent landowners, along with a place on an artificial island in Miami Beach, a large house in Washington and compounds in California and Hawaii.
A spokesperson for Mr. Zuckerberg, the 42-year-old billionaire chief executive of Meta, confirmed this week that he had bought the castle, a Gothic-style estate in Waterford County, a region of southeastern Ireland with about 130,000 people. The castle was built around 1830 and renovated in the early 2000s.
The purchase does not appear to be listed in Ireland’s property price register. The Irish Times, which reported the news on Thursday, estimated that the estate could be worth $23 million to $35 million.
Around the middle of the 19th century, the estate was valued at 61 pounds, according to an entry about the castle in a University of Galway archive of landed estates that also mentions it contained an art collection and a library.
The castle was built for a former member of Parliament, John Keily, according to Ireland’s National Built Heritage Service, which describes the building as both “muscular” and “dour.”
The estate has never left private hands, leaving the public to glimpse its interior only in historical archives. An entry about Mr. Keily in “The History of Parliament” website says the house was designed “on a lavish scale; it took a brisk walk of 4½ minutes to reach the dining room from the kitchen.”
It is not clear how much time Mr. Zuckerberg or his family (he has three daughters with his wife, Priscilla Chan) will spend in Ireland, but his company has a significant presence there.
Like many major U.S. companies, Meta uses an office in Dublin as its European headquarters, and about 1,500 employees work there. Ireland has become a hub for multinational corporations, both for its relatively low corporate income tax rate, 15 percent for big companies, and its history of allowing corporations to shift profits out of the country into places like Bermuda, Grand Cayman and the Isle of Man.
Ireland’s status as a base for several technological giants has made it a key player in enforcing European Union regulations and, increasingly, a center of protest against the companies and their data centers.
Asked for comment about Mr. Zuckerberg’s purchase, the Waterford City and County Council extolled the area’s attractions — wild coastlines and mountains, picturesque festivals and towns — and the history of the county and city.
“Founded by the Vikings in 914 AD, Waterford is Ireland’s Oldest City that has been shaped by centuries of history and today it is evident that the county’s remarkable architecture keeps its past vividly present,” the council said in an email.
“We hope that Mr. Zuckerberg and his family fully enjoy all that Waterford has to offer.”
