The building is an unexpected sight in a town this remote: a cream-painted lower storey and a warm, reddish-brown brick upper floor, wrapped on three sides by a deep two-storey verandah. The style is Victorian Filigree, named for the lacework of cast iron that decorates it - green-painted posts, white brackets, a curved timber valance running like a fringe beneath the eaves. That verandah is not mere decoration. In a place where summer temperatures climb past 40 degrees, the shaded wraparound balcony was a practical answer to relentless heat, drawing air through the rooms and keeping the brick from baking. Twin corbelled chimneys rise from the roof. It is the kind of architecture that announced a town had arrived, and Bourke, in 1880, very much had.

Bourke got its first post office in 1862, run out of a merchant's premises by a clerk named Joseph Becker. As the river trade boomed through the 1870s, the rented rooms could no longer cope. In 1877 a site was chosen beside the Court House, and the builder E. Heseler eventually won the contract; the new single-storey office opened in 1880. It was almost immediately too small. White ants chewed the timbers, the roof leaked, and the postmaster, required by regulation to live above the shop, needed more room. So in 1889 an entire second storey was added, along with the wraparound verandah that gives the building its character today. By 1890 Bourke handled so much postal and telegraph traffic - serving western NSW and the southwest of Queensland - that it ranked among the most important offices in the colony.

For more than a century this was where Bourke spoke to the world. Telegraph operators tapped out messages that crossed hundreds of kilometres of empty country; station owners learned wool prices here, families sent news, and the lonely outback was stitched, however thinly, to Sydney and beyond. The post office did far more than move mail. It acted as a savings bank, an electoral office, a telephone exchange - the single civic hub where the business of a scattered community was conducted. Standing close to the Court House and the bank, it formed the heart of a small precinct of public buildings, the proud civic core that boom-town Bourke built for itself while the river money flowed.

The riverboats faded once the railway and the roads took over, and Bourke shrank from its frontier heyday. But the post office endured. It still operates as an Australia Post branch, its retail counter tucked into a building that has watched the town's entire modern history unfold. A tall Telstra communications tower now rises behind it - a strange echo, in steel and antennas, of the very purpose the place has always served: keeping a remote community connected. Listed on the New South Wales State Heritage Register in 2000, the building is prized as a fine example of its style and as a tangible record of the riverboat era, when a port on the Darling thought itself, for a moment, the centre of the world.