[1] The hospital buildings are now part of the Irish Department of Defence's (An Roinn Cosanta) estate and currently houses Ireland's Office of the Director of Public Prosecutions (Oifig an Stiúrthóra Ionchúiseamh Poiblí - ODPP).

[15] In 1910, the British Government had not decided on a purpose for the old hospital building[16] In 1910, Lieutenant Colonel O Birt, was posted as the senior medical officer in charge of the Royal Military Infirmary.

[18] The RMI and all other British Military installations fell under the direct control of the Irish Free State (Saorstát Éireann) in 1922 and the Department of Defence became the managing entity of the old Infirmary site and that remains the case to the present day.

The original main three-storey building was designed with a C-shaped footprint; it was built of granite blocks faced with Portland stone.

The main facade (circa 60 metres in width) faces southwest on raised ground overlooking the southern entrance of Phoenix Park.