Dublin Castle (Irish: Caisleán Bhaile Átha Cliath) is a major Irish government complex, conference centre, and tourist attraction. It is located off Dame Street in Dublin, Ireland.
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 complex.
We took the underground tour, which included seeing the Poddle and the foundations of the original castle, ans well as wandering through the various rooms of ostentation.
There was a display of artwork based on heads all though the castle, whihc is why there are random heads.