Just outside Trinity College stands Marsh’s Library, founded by Archbishop Narcissus Marsh in the early eighteenth century and opened to the public in 1707. Marsh was a scholar, theologian and book collector, and his connection with Trinity was a significant one. He had previously served as Provost of the college.

But the library is associated with a much more personal ghost story.

Marsh had no children of his own, but he was guardian to his niece Grace, whom he raised with great affection. When Grace reached nineteen, she fell in love. Exactly who she fell in love with depends on which version of the story you believe. Some accounts say she fell for a sea captain. Others identify him as Charles Proby, the Vicar of Castleknock. What is consistent is that Marsh strongly disapproved.

So Grace decided to elope.

Before leaving, she is said to have written a note to her uncle explaining what she had done and asking his forgiveness. The letter was supposedly hidden inside one of the books. One version says Marsh never discovered it. Another claims that he found it but, overcome with grief, hid it away himself, only to forget where he had put it.

Whatever version you prefer, the result is the same. Marsh died without the letter being found. And so, according to the legend, his ghost still wanders the library, searching through the books for something that has been lost for centuries. Staff have also reported unexplained rustling pages, cold spots and the faint smell of pipe smoke – a particularly appropriate detail given Marsh’s fondness for his pipe.

Next door, in St Patrick’s Cathedral, lie Jonathan Swift and his companion Stella. Local tradition holds that Swift’s ghost occasionally visits the library to look at the replica of Stella’s skull.