Whilst the building marked as ‘Hampstead Castle’ on the 1837 Ordnance Survey map was demolished around 1869, historical records suggest it may have been built on the site of, or even incorporated parts of, a 17th-century fortified house or manor house that bore the same name. The earliest documented reference to the land dates back to 1709, when Sir John Rogerson, famous for Dublin’s Rogerson Quay, owned the area south and west of Hampstead House. Deeds from this period intriguingly mention two houses on the land; one built by Rogerson himself, and another described as having ‘a court walled in with stone before it’, believed to be the original Hampstead Castle.

John Rocque’s detailed 1756 map of Dublin provides our best glimpse of the castle’s appearance, depicting it as a rectangular structure aligned north to south along its long axis. The building featured what appear to be flanking wings on either side of the central structure, all overlooking a formally designed entrance to the east, with a large walled garden extending to the west. This same layout appears on Taylor’s 1816 map of Dublin, where both the building and its walled garden are clearly annotated as ‘Hampstead Cas.’

The castle’s story came to an end in 1869 when it was demolished, but its legacy lived on in an unusual way; the stone from the demolition was repurposed to construct Elmhurst House, located just 125 metres to the south. The land directly south of the castle, comprising 16 acres, had been leased in 1775 to Sir Richard Steele of Bettyville, County Carlow, and it was on this plot that Elmhurst would eventually rise, built quite literally from the bones of the old castle.