This imposing tower house dates from the late 16th to early 17th century, when Sir Thomas Fitzgerald constructed it, though he cleverly incorporated portions of an earlier medieval castle that had occupied the site since the 13th or 14th century. The structure rises three storeys high, with a distinctive string course marking where the parapet level begins.

The castle's construction tells its own story through the materials used; the walls consist mainly of randomly coursed granite blocks, whilst the more refined elements such as window and door jambs feature dressed limestone, showing the care taken in these architectural details. The main entrance, located at the southern end of the eastern wall, appears to be a later addition with its rough hammer-dressed jambs supporting a segmental arch above.

Close examination of the doorway reveals fascinating defensive features that speak to the castle's turbulent past. The door itself is rebated, sitting flush within its frame, and visible bolt holes indicate where heavy bars would have secured the entrance against unwanted visitors. These practical details, combined with the tower's commanding position above the river valley, demonstrate how the castle served both as a comfortable residence for the Fitzgerald family and a formidable defensive stronghold in County Dublin's often unsettled medieval landscape.