Although there is no visible trace left of the 1172 castle, the ground has always had a castle ever since then. The possession of the castle changed several hands in its long history till 1957. It was temporarily possessed by Knights Templar before their suppression in 1308. At one point of time in the 16th century, it was under the control of the British crown as well. From there on it became the property of Vernon family and also had other owners subsequently. Finally, the castle re-opened to general public in June 1997 as a four star hotel with 111 rooms for guests.
The present structure of Clontarf Castle traces its genesis to 1837 when it was still part of the Vernon Estate. The brain behind the design of this splendid castle is of an Irish architect named William Vitruvius Morrison. He was commissioned for the work when the old building was deemed to be unsafe to live in. The structure underwent further renovations when it was converted into a hotel that has all the modern facilities and amenities. As a result, most visitors always find their stay at this magnificent castle turned hotel pleasurable and memorable.