I would love 23 Cambridge Terrace to be in Monkstown, even if 23 Cambridge Terrace is absolutely not in Monkstown and even if Savills estate agents are fraudulently describing it as being in Monkstown.
That’s the civil parish of Monkstown. The civil parish definitions go back to the plantations of the 16th-17th centuries. In the case of Monkstown it was the boundary of the Carrickbrennan estate, taken from the Cistercian monks by Henry VIII in 1539 and given to one of his military henchmen. The ecclesiastical parishes, on the other hand, have changed with the times. Dun Laoghaire didn’t really exist until the harbour was built, except as a small bunch of houses where the West Pier service station is now. After that time, and especially upon arrival of the railway, Dunleary/Kingstown outstripped Monkstown as the local big smoke. Even in my father’s earliest memory (born 1917 – he remembered British soldiers on the street in Sandycove) you could stand on top of Dalkey hill and see only the big old mansions of Glenageary and Monkstown surrounded by agricultural fields, with Dun Laoghaire being the main cluster of buildings at least as far as Dublin 4 or beyond.