If you want to visit or see castles as they are in Disney creations this is not for you - don't waste your time visiting.
Many visitors are surprised and often disappointed when they visit Dublin Castle because it does not look anything like a castle should look like. One section that looks like a castle is a church. However, if you undertake a guided tour you may be surprised by what is to be seen.
Dublin Castle is a working castle and because of this sections have been destroyed [major fire in 1684], replaced, added and redecorated over a very long time and it ended up being a centre of administration.