Built between 1208 and 1220, this complex represents
some of the oldest surviving architecture in Dublin,
and was the centre of English power in Ireland for over seven centuries
until it was taken of by the Irish Free State in 1922.
Highlights include the 13th-century record tower,
the largest visible fragment of the original Norman castle and the State Apartments,
once the residence of English viceroys
and now the focal point for government ceremonial functions,
including the inauguration of Ireland's presidents.
The newest developments for visitors are the Undercroft,
and excavates site on the grounds where an early Viking fortress stood,
and the treasury, built between 1712 and 1715,
believed to be the oldest surviving purpose-built office building in Ireland.