With its remarkable green dome and long colonnaded façade, the old Custom House was built by James Gandon and completed in 1791. The building was severely damaged by a fire at the start of the Civil War in 1921 but was subsequently restored. The visitor centre is the main hall, behind the south portico, virtually unchanged since Gandon's time. The exhibition charts the history of the building from its construction, the fire and restoration, Gandon's career and the work of the ministerial departments that occupy the building today.