Dublin Castle Ireland (1800–1922). After the signing of the Anglo-Irish Treaty in December 1921, the complex was ceremonially handed over to the newly formed Provisional Government led by Michael Collins. It now hosts the inauguration of each President of Ireland, and various State receptions. The castle was built by the dark pool ("Dubh Linn") which gave Dublin its name. This pool lies on the lower course of the River Poddle before its confluence with the River Liffey; when the castle was built, the Liffey was much wider, and the castle was effectively defended by both rivers. The Poddle today runs under the
Newcastle (County Dublin barony) Newcastle (County Dublin barony) Newcastle () is a feudal title of nobility and one of the baronies of Ireland. It was constituted as part of the old county of Dublin. Today, it lies in the modern county of South Dublin. At the heart of the barony is the civil parish of the same name - Newcastle - which is one of eleven civil parishes in the barony. The ruins of the eponymous castle, also known as Newcastle-Lyons, are located in the townland of Newcastle South. The town with the biggest population in the barony is Lucan. It is one of