Dublin Castle

King John of England ordered the castle built in 1204 as a fortification, beside the dark pool, the Dubh Linn, that gave the Norse settlement and later the city its name. Of the medieval castle only the Record Tower, from around 1228, survives. After a fire in 1684 the complex was gradually rebuilt as a palace in Georgian style. It remained the centre of the British administration until 1922, when it was formally handed over to the Provisional Government led by Michael Collins.

The State Apartments in the southern range were once the quarters of the Lord Lieutenant and are still used for state ceremonies; Irish presidents have been inaugurated here since Douglas Hyde in 1938. The grandest room is St Patrick's Hall with its painted ceiling by Vincenzo Valdre. Below ground you can see medieval excavations, including remains of the Viking defences and arches over the River Poddle.

The Chapel Royal stands in the grounds, and the Chester Beatty Library, with its collection of manuscripts, is housed in its own building beside the Dubh Linn Garden.