History and Significance Learn about the GPO Building’s historical significance to shaping Sydney’s urban grid and its contribution to Australian architecture and culture. CONSTRUCTIONLearn about the 25 year construction process under the guidance of Colonial Architect James Barnet. SIGNIFICANCEDiscover why the GPO building was hailed as a turning point for the people of New South Wales. Connection to the Indigenous Gadigal people The site of the Sydney GPO falls within the traditional country of the Gadigal people. 1997-99 RedevelopmentLearn about the restoration and redevelopment of the building beginning in 1996. how do you place value on an icon? Deloitte, 2013. How do you value an icon? Retrieved here.