Dublin Castle has been at the center of Irish life since King John of England ordered its erection in 1204. Standing over much earlier structures including a Viking fortress and, possibly, a Gaelic ringfort, it forms the social and political heart of historic Dublin. Visiting Dublin Castle, you’ll get to see the majestic State Apartments, the Viking ruins underneath, and the ancient Black Pool where the river Liffey meets its underground tributary the River Poddle. The seat of British administration in Ireland for 700 years, this glorious collection of buildings recounts the history of Dublin like no other.