Known as the 'Post House', it had begun its life on High Street before being relocated bodily to Fishamble Street, a practice that was less unusual in early modern urban life than it might seem today, when whole timber-framed structures could be dismantled, carted through a city, and reassembled on a new plot. What makes this particular building quietly remarkable is not just the fact of its relocation, but how thoroughly it has slipped from the record. No precise address survives, no image, no deed of removal. It exists now only as a single line in the historical literature.

The sole source for the Post House is J.W. de Courcy's 1996 study of the River Liffey, which notes the building's original position on High Street and its subsequent move to Fishamble Street without providing further detail about when the move took place or who was responsible. Fishamble Street itself runs down from Christchurch toward the old quays and is one of the streets in Dublin where the Viking-age and medieval layers of the city sit closest to the surface, quite literally so given the significant archaeological excavations carried out in the wider area during the late twentieth century. High Street, where the Post House first stood, was a principal artery of medieval Dublin, lined with merchants and tradespeople. The name 'Post House' likely refers to a function connected with communications or the collection and dispatch of mail, though de Courcy does not elaborate on this point.

Because the Post House cannot be precisely located, there is no standing structure to visit and no plaque to find. What a curious visitor can do is walk both streets with some awareness of the building's ghost, so to speak. Fishamble Street is short and steeply graded, and it retains a slightly compressed, canyon-like quality despite the changes of recent centuries. The street is also associated with the 1742 premiere of Handel's Messiah at the since-demolished Musick Hall, so it is already a place where vanished buildings carry a certain weight. High Street, meanwhile, has been heavily altered by road widening and twentieth-century development. The Post House belongs to a category of Dublin's built heritage that is genuinely irrecoverable, known just enough to be tantalising, but too sparsely documented to be fully understood.