Dublin castle is considered the historic heart of Dublin. Before the castle, the grounds were used for a Danish Viking fortress dating back to the 930’s. This area quickly became the major Viking military base and trading post. In 1169, the Danish Viking fortress was taken over by Normandy. A stronger and larger fortress was built in its place. In August of 1204, King John of England had an even larger castle built, which the layout corresponds closely to the present day Dublin Castle. Currently, the south east tower is the only remaining medieval tower in Dublin Castle and in all of Dublin. Previously, the tower was used as a prison and to house Irish hostages. Many of the other towers have been rebuilt or modified and their uses have changed drastically over the years. The history is incredible. The castle has been used to house Royalty, and allow their businesses, as a prison, and as a military barricade. By 1570 the castle had become absolutely ruined, and a thirteen year remodeling project was put in place. Many wars and regime changes have occurred since the castle was erected. Fortunately for Ireland, and its millions of visitors, the castle remains as a testament to the nation’s rich history and beautiful architecture.