Historic mapping artifacts

Ordnance Survey Ireland has evolved from the Ordnance Survey Office which was established in 1824. This Office was initially part of the army under the Department of Defence. All staff employed by the Office were military until the 1970s when the first civilian employees were recruited.

The Ordnance Survey Office was created to carry out a survey of the entire island of Ireland to update land valuations for land taxation purposes. The original survey at a scale of 6 inches to 1 mile was completed in 1846 under the direction of Major General Colby. Ireland thus became the first country in the world to be entirely mapped at such a detailed scale.

Ordnance Survey Ireland History

In the course of surveying the country, the staff of the Office was responsible for a number of advances in surveying practice. These ranged from Drummond’s limelight to the bimetallic parallel bars used to measure distance to a previously unattainable level of accuracy. The drive to improve technical capability has continued to remain a prime value in ordnance survey work to the present day.

The Office was located in Mountjoy House in the Phoenix Park. Mountjoy House was originally built in 1728. It later housed the mounted escort of the Lord Lieutenant who resided in the Vice-Regal Lodge (now Aras an Uachtarain). Mountjoy House and its surrounding buildings still serve as our headquarters.

The Office continued to operate under the agency of the Department of Defence for 80 years until 1924 when central responsibility for it was transferred to the Department of Finance.

Ordnance Survey Ireland operated as part of the civil service area of Government until 2002 when it became a state body under the Ordnance Survey Ireland Act 2001. Under this Act, Ordnance Survey Ireland continued its mainstream public service function of creating and maintaining the definitive mapping records of the State and also assumed the commercial function assigned to it under the Act of developing its commercial business and sales revenues.

Central responsibility for Ordnance Survey Ireland was transferred from the Department of Finance to the Department of Communications, Energy and Natural Resources with effect from 1st January 2008.

To-day, Ordnance Survey Ireland employs 235 staff located in Dublin’s Phoenix Park and in our six regional offices in Cork, Ennis, Kilkenny, Longford, Sligo and Tuam.