originally constructed in 1865–66 to the design of Colonial Architect, Charles Tiffin, and subsequently extended, is the oldest post office known to survive in Queensland, and is one of three remaining masonry post offices from the period between Queensland's separation from New South Wales in 1859 and the amalgamation of the post and telegraph departments in 1878. Its scale and imposing presence, including the prominent clock tower, is demonstrative of the growing regional importance of Maryborough in the nineteenth century. Its many additions and changes also reflect the need to physically update and adapt the building to Maryborough's prosperity and development. Criterion B: Rarity The Maryborough Post Office is the oldest post office known to survive in Queensland, and one of three remaining masonry post offices from the period between Queensland's separation from New South Wales in 1859 and the amalgamation of the post and telegraph departments in 1878. Criterion D: Characteristic values Maryborough Post Office is an example of: a post office and quarters (first generation typology 1803–1869), with tower a building in the Renaissance Revival / astylar Italianate style\ the work of the Colonial Architect's office under Charles Tiffin (1865-6); FDG Stanley (1875-9, tower extension); JJ Clark (1882-5); and Alfred Brady (1896-1906). The 1925 alterations may have been under JS Murdoch's Federal jurisdiction. Typologically, the original building comprised a post office and residence with tower, but relatively quickly accommodated the addition of a single faced clock in 1869 to the third level of the tower. Later nineteenth century works which impacted on the original form and planning include the enclosure of the loggias, a further storey added to the corner tower, a new wing constructed to house the expanding telephone exchange operation, a timber-framed balcony to the first floor level of the postmaster's quarters; and a variety of other internal and external alterations and additions in the twentieth century. These later works have impacted and diminished the typological attributes of the building Stylistically and architecturally, however, the building retains its Renaissance Revival and Italianate styling, as per Charles Tiffin's original design, including the symmetrical composition of a prominent corner clock tower flanked by arcaded loggias in antis between flanking pavilions and layered arched windows. Criterion E: Aesthetic characteristics Maryborough Post Office is a key historic building within the centre of Maryborough, one of the most significant buildings in the town, and complemented by the Post Office Hotel opposite.