The heritage precinct also includes the former court house and jail, an area designated as a government reserve for much of the township's history.

[5] It is located on the corner of the Bruce Highway and Balliol Street at the southern end of the town and is immediately adjacent to the also heritage-listed Cardwell Divisional Board Hall.

A substantial government infrastructure was established in Cardwell, including a pilot's quarters, police barracks and lockup, court and customs house, post magistrate's residence, sub-collector's residence, lands office, and telegraph station, which reflected this enthusiasm.

The extension of a telegraph line from Bowen to the Gulf of Carpentaria was considered desirable for two main reasons; to serve the settlers in the area, and there was the possibility of joining the proposed overseas cable from Java.

The Queensland Government hoped the connecting cable linking Australian to Asia and then to Europe would enter Australia through the Gulf of Carpentaria.

[5] Tenders had been called in September 1869 for the erection of telegraph lines from Cardwell to Gilberton and then to the Gulf of Carpentaria, and the two sections were completed in 1871 and 1872 respectively.

Townsville became the principal access point for inland travel, and rapidly bypassed Cardwell in growth and development.

As well as being significant in the history of the port of Cardwell, the Cardwell-Normanton telegraph line was a lifeline for the isolated people of this region.

However, the building was reconstructed closely to match its original timber appearance, with the stage area fortunately being retained within the rebuilt hall.

The resulting historic precinct presents a fine example of the workings and economics of colonial administration over a large thinly populated area, and the nineteenth century technology that coped with it.

Queensland State Archives and the National Archives of Australia yielded original specifications, plans, documents describing repairs and requirements and requests from staff for new chairs and a new clock, for example, allowing a good picture to be developed of the original construction of the building as well as changes it underwent through time.

Visitors to this heritage centre can view the original postal room with its old telephone exchange and 1870s counter and check out the old weather station instruments.

A message can be sent by Morse code and an interactive display demonstrates Cardwell's role in the telegraph line race between Queensland and South Australia.

In the courthouse, the workings of local justice are displayed while the lock-up next door provides a firm reminder of the pioneering days of the north.

Next to the library, which is also a Cassowary Coast Customer Service Centre, a large outdoor display facility houses local artefacts including an old tip dray and a spring cart which was used in the area for many years.

Cross-cut saws, a hand plough, a banana-case making machine, railway construction implements and other items are exhibited.

[5] The building is a single-storeyed timber structure, consisting of four rooms with a central corridor, surrounded by verandahs to all four sides with a kitchen house at the rear connected by an enclosed walkway.

[5] The northeast verandah, and much of the northwest, has been enclosed with corrugated fibrous cement sheeting and has both timber sash and aluminium sliding windows.

[5] The single-skin building has weatherboard to the verandah walls with beaded horizontal boarding to the inside face of the two northeast rooms.

[5] The northern room was used as the post office and retains some early timber fixtures including shelving and drawers.

It demonstrates rare aspects of Queensland's cultural heritage, in particular, it is one of the oldest and one of the few extant telegraph/post office buildings erected c. 1869–c.

The place is important in exhibiting a range of aesthetic characteristics valued by the community, in particular the contribution of the buildings and grounds, through siting, scale, form and planting, to the Victoria Street streetscape and Cardwell townscape and the intactness, in particular the plan, form and interiors of this timber and iron building.