



Tunnels underneath Leinster House
Lets visit the tunnels underneath Leinster House! Some of the underground areas are historic but many are distinctly modern constructions. The seat of our Oireachtas was originally called Kildare House, and it was a grand ducal palace of James FitzGerald, 20th Earl of Kildare, between 1745 and 1748.
Designed by architect Richard Cassels, the building was tragically left unfinished when Castle died in 1751, supposedly at his desk at Carton House writing instructions to a carpenter at this very site. Isaac Ware stepped in to complete the interiors, with James Wyatt later finishing the grand public rooms in the 1770s.
Its name changed to Leinster House in 1766 when the Earl FitzGerald was elevated to the first Duke of Leinster. He was a bit of a gobshite. After the Act of Union in 1800, the building's importance as a ducal residence greatly diminished.
Which reminds me of the White House connection. The Kilkenny-born architect James Hoban had studied at the Dublin Society's School of Architectural Drawing nearby on Grafton Street. When he won the competition to design the presidential mansion in Washington in 1792, he used Leinster House as a model. The front facade, the triangular pediment, the arrangement of windows, all lifted wholesale from Cassels' Dublin masterpiece.
In 1815, the 3rd Duke of Leinster sold the gaff to the RDS (Royal Dublin Society). Eventually the equally elegant National Museum, the National Library, and the often-overlooked Natural History Museum wings were added around the complex. This period facilitated wider integration of sub basements across the whole historic neighborhood.
The next great evolution of Leinster House came in 1922, when Michael Collins arranged to lease the building from the RDS as a temporary home for the Irish Free State's parliament. The Dáil took over the large lecture theatre, the Seanad was installed in the Duke's old ballroom, and the rest is history. The building was formally purchased in 1924.
But back to them tunnels. A 2008 OPW report, delivered to the Ceann Comhairle's office, warned that Leinster House presented a serious risk to the safety and health of its occupants without major remedial work. The building underwent massive restoration from December 2017 until August 2019. Periods of maintenance like this are ideal opportunities for sub rosa construction. An observant eye may find this view of our temple of democracy interesting oireachtas.ie/en/visit-and-l…
The most recently publicly disclosed addition to the system was labelled as connecting the campus to the Department of Agriculture headquarters down the street and cost about €1m around 2012. Much of Agriculture House was vacated when the bulk of its staff were decentralised to Portlaoise, allowing the Houses of the Oireachtas facilities to take over.
Rumour has it other subterranean corridors were also added when Leinster House was being made disability compliant by the end of 2011, and again during a period of extensive conservation of stonework and roofing in the last decade.
The usually undiscussed underground system got a rare mention in the news in 2022 when staff and politicians were asked to travel via underground tunnels after Fine Gael Minister of State Peter Burke became unwell addressing the Seanad on the Water Environment Abstractions Bill. The Seanad was suspended for several hours and multiple corridors leading to the front of the building were closed off while an ambulance brought him to hospital were he recovered.