The Mansion House most famous features include the “Round Room”, where the First Dáil assembled on 21 January 1919 to proclaim the Irish Declaration of Independence. On 21 January 1969 a special fiftieth anniversary joint session of Dáil Éireann and Seanad Éireann assembled there and was addressed by the then President of Ireland, Éamon de Valera.
MANSION HOUSE DUBLIN Ireland - Lord Mayor of Dublin, Official Residence Built in 1710 - Visit Dublin
The Mansion House was built in 1710 by the merchant and property developer Joshua Dawson, after whom Dawson Street is named. Dublin Corporation purchased the house in 1715 for assignment as the official residence of the Lord Mayor. It retains this purpose to this day.In the 1930s and 1940s, plans were made to demolish the building, and all other buildings on the block on which it is located (which covered an area on Dawson Street, Molesworth Street, Kildare Street and the North side of St. Stephen's Green), to enable the building of a new Dublin City Hall. However the decision of the Government to erect a new Department of Industry and Commerce on a site on the same block, on Kildare Street, led to the abandonment of the plans.