Following temporary military arrangements after the 1798 Rebellion, the Pigeon House Fort was created, and maintained by the Department of War from 1814 to 1897. At its peak, it included gates with drawbridges, quarters for officers and men, a hospital, armoury, magazine and stores. The fort was heavily armed and garrisoned to protect Pigeon House Harbour. The harbour was intended to be used as a last ditch exit point from Ireland for the British in the event of a successful Irish rebellion
In 1897, the complex was sold to Dublin Corporation and absorbed into a complex of electricity generating stations and waste water treatment works.All that remains today of the former Pigeon House Fort is part of the gateway and a section of sea wall complete with gun loops.