An architectural competition was announced in 1768 by the Merchants Guild of Dublin for a new Royal Exchange on Cork Hill. Thomas Cooley, a Londoner, won the commission and construction started a year later. It would take 10 years to complete the magnificent building.
In 1851 the Merchants Guild sold the building to Dublin City Council. The upstairs Coffee Room was converted into the Council Chamber, and the central rotunda was left largely intact but temporarily partitioned into offices. The building was briefly occupied by rebels during the 1916 Easter Rising. Today the City Council still meets here under the chair of the Lord Mayor. The rotunda space is frequently used for civil weddings, exhibitions and launches. Outside of these events he ground floor is open to visitors.
https://www.dublincity.ie/business-and-events/hire-venue-or-park-event/city-hall