The former Richmond Barracks in Inchicore is be transformed into a major interactive multimedia centre in time for the commemoration of the 1916 Centenary next Spring.
The leaders of the Irish revolution, along with over 3,000 Irish rebels from all over the country, were held in the barracks in the aftermath of the 1916 Rebellion before they were either sentenced or released.
This included the seven signatories to the Proclamation of Independence who were then executed in Kilmainham, as well as future key players in Irish history including Michael Collins, Eamon De Valera, Arthur Griffith, and William T Cosgrave.
The redevelopment will take place over the next six months.
When complete, the interactive tourist attraction will trace the story of the site from military barracks to its use as a housing estate and Christian Brothers school after the site was turned over to the Free State Army in 1922.
There will be flexible event and exhibition spaces, an archive of artefacts relevant to the building's 200-year history, gardens, cafes, and installations from local artists, and it will provide a space of education and heritage for the local community and visitors to Dublin.
Turning the sod yesterday, Lord Mayor Criona Ni Dhalaigh said the barracks played a central part in the history of 1916.
"Beyond 1916, it also provides a fascinating insight into the social history of working class Dublin in the 20th Century. It is essentially a lost chapter in Irish history and once the redevelopment is complete, we will see this unique site reclaim its rightful place in local and national history," she added.
Built in 1810 in response to the threat of a French invasion in the Napoleonic Wars, nearly every British Regiment would spend time at the Richmond Barracks, and fighting in conflicts including the Crimean War, Boer War, and World War 1.
In 1916, the Rebellion leaders were sorted out of the crowd of Volunteers and set aside in the barracks gymnasium to await their fate.
Richmond Barracks continued its military use until 1924 when it was renamed Keogh Square and converted into social housing. Tenants lived until 1969, while St Michael's CBS operated on part of the site from 1898 to 2007.
Also at the sod-turning event, children from Our Lady of Lourdes NS in Inchicore were presented with the national flag and a copy of the Proclamation by a member of the Defence Forces as part of the Ireland 2016 Centenary Programme.