A TAXI driver brought a US tourist to Dublin Castle instead of Ardgillan Castle - located 35 kilometres away - and told her the two attractions "are the same thing".
Jacquelyn Mitchard said she was left "sad and disappointed" after missing out on the visit to Ardgillan, which has partly inspired her next novel.
Mitchard - a best- selling author whose award- winning novel The Deep End of the Ocean has been adapted into a Hollywood blockbuster - said she repeatedly raised concerns and tried to tell the driver he was going to the wrong place.
However, she says the driver "insisted" on dropping her off at the city centre attraction.
The incident occurred last Saturday when the novelist's family got into a taxi near Lansdowne Road.
The author, who has won multiple awards for her books, was in Dublin with her two children, where she was a special speaker at the Abroad Writers' Conference.
The family had booked afternoon tea in Ardgillan Castle, which is near Balbriggan.
Jacquelyn explained that Saturday was her only day away from the conference before she and her family flew back to the US.
She said they had been "hugely looking forward" to the event on the final day of their trip to Dublin, but were left "very let down" when they got out at Dublin Castle and realised they were in the wrong place.
"I kept insisting to the taxi man. I kept saying 'it's not the right place, it's not, it's not' but he said 'No, they're all the same. They're all one place'," Jacquelyn told the Herald.
"Of course, I'm an American. I have no idea what was right or what wasn't and then we got there and we asked around and it became clear we had made a mistake.
"We didn't know what to do and we looked at how long it would take to get out to Ardgillan. We were 45 minutes away. There was no hope of making it in 15 minutes."
The family contacted Tom Reilly, property manager at Ardgillan Castle, who offered to arrange transport to ensure they made it to the castle. However, it was too late, as the family had to get a flight back to the US.
Jacquelyn said she was blown away by the kindness and generosity shown by the staff at Ardgillan Castle and said she will make it to the castle next year.
A spokeswoman for the National Transport Authority said it was "most unfortunate" the family met an operator "who did not live up to the great reputation our drivers have, especially with our visitors."