The Great North Road, which aimed to link Sydney with the Hunter Valley, was constructed between 1826 and 1836. In the 1820s, some 35 years after initial British occupation, the colony of NSW was expanding, with exploration pushing the limits of settlement and permanent communities and towns being established. By 1822, with the relocation of the convicts to Port Macquarie, Newcastle was no longer a penal settlement and unlike the pastoral Bathurst Plains, the Hunter Valley was particularly promising for agriculture, due to its alluvial soils and the possibility of sea and river transport.

Governor Ralph Darling, who arrived in 1825, wanted to provide the colony with an all encompassing and permanent road system, modelled on the Great Roads of England. The extensive works required for the construction of the descents and ascents on both sides of the Hawkesbury River, required a large convict labour force to be stationed there from 1827 - 1832. After Wisemans Ferry, the road continued north via Mt Manning and Mt McQuoid to Wollombi. It then branched, with one line to Maitland and another to Patricks Plains (Singleton).

The road which scaled the precipitous and mountainous terrain between Wisemans Ferry and Mt Manning, utilised cut and fill construction on hillsides, creating roads which wound and zig-zagged on ascents and descents. It required the blasting and cutting away of rocky spurs, and the construction of the impressive and durable formations and structures which mark the second and third construction phases of the Great North Road, such as the ashlar masonry retaining walls on the ascent of Devines Hill. By 1832 the substantial structures over the stony mountains, ridges and gorges were mainly complete and the convicts who had acquired skills in their construction were shifted to other Great Roads. These were the Great Western Road (from Sydney to Bathurst and thence Wellington) and the Great South Road (from Sydney via Goulburn to Yass and the Monaro Plains).

The Great North Road is an item of National heritage significance. It has values under all relevant heritage assessment criteria, including historic, aesthetic, scientific and social significance. The Great North Road is significant for the following reasons:
It has historic significance as a signifier of the outlooks of early colonial society. Its magnificent structures were powerful, tangible symbols of the colony's perceived place and role in the course of empire, unmistakable evidence that the civilised state was being attained, and a triumph over the rugged and inhospitable landscape separating the centre of Sydney from the "garden of the colony", the Hunter Valley.
The Great North Road is associated with several notable figures in colonial administration, surveying and engineering, including Governor Ralph Darling; Surveyor-General Sir Thomas Mitchell, Heneage Finch and Percy Simpson. Prior to its selection and survey by Europeans, much of the route which later became the Great North Road, was in use as an Aboriginal route linking the tribal groups of the Hunter Region to the Hawkesbury.
Individual structures found along the Great North Road are aesthetically attractive. Structures such as the Devines Hill buttressed retaining wall and items such as Clares Bridge and Circuit Flat Bridge have aesthetic value in their design, execution and siting. Some of these structures are shown on this page.
The Great North Road has historical archaeological significance in that it physically demonstrates the work patterns, skills and organisation of the convict road gangs, particularly through the distribution and configuration of the stone retaining walls, drainage structures and bridges. This evidence is unavailable in documentary sources and has been essential in changing our historical views on convicts in road gangs. The Road may be considered a museum of convict work, graphic in its demonstration of the difficulty, laboriousness and isolation of 1830s road building.
The Great North Road has historic / scientific value in its demonstration of the standards and practice of road engineering in the colony during the "Great Roads" period of the late 1820s and 1830s, and records the importation and adaptation of the (then) recent road-building revolution in England. This essential information is unavailable in documentary sources, and as such it has changed our understanding of Australia's road engineering history.
Many precincts of the Road still demonstrate the nature of nineteenth century travel, through their early style geometry and layout, including sight-lines and tight curves, and with structures passing through the original landscape and vegetation.
Specific associated sites and items along the Great North Road are significant for their archaeological research potential. This includes for example, the various convict road station (stockade) sites such as those at Wisemans Ferry and on Devines Hill, the hut site at Frog Hollow and the former property of Heneage Finch at Laguna.