This property has high regional significance as the site of large Scout Jamborees in 1948-49 and 1955-56, and of the 1961 World Scout Moot, significant events for Victoria. Extensive evidence remains of these scouting activities, some within Clifford Park and other features within the Warrandyte State Park. Clifford Park has historical significance for its associations with Lord Clifford, successful businessman with a long interest in scouting, and owner from c1940 of the Yarra Brae property, the site of Clifford Park created after the 1948 Jamboree. (Criterion A4, H1)
Within Clifford Park, extensive evidence of the Pan Pacific Jamborees of 1948 and 1955 and of the 1961 World Rover Moot remains. Some of the features are within Clifford Park, while others are now within the Warrandyte State Park.
Within Clifford Park are located:
- extensive areas with levelled camp sites, most overgrown
- footings of the stage used at the Jamboree
- bases of the large boomerangs used first at the 1956 Olympics
- flagpole (near boomerang bases)
- three large eucalypts visible in photographs of the Jamboree
- recent chapel c1989.
Within the State Park, there are (at least) the following sites:
- toilet block and storage building (near Rowallan Hall).
- Rowallan Hall, a timber framed building, externally clad with vertical weatherboarding.  The Management Plan records that the building was moved here from Frankston, however John Upton recalls that it was built by John Wolt with volunteer local labour prior to the 1948 Jambouree. The building has been removed (with parts reused within Clifford Park and elsewhere); the concrete floor remains.
- near Rowallan Hall site are four 'tables' dug by the Latvian scouts at the Jamboree
- swimming hole in the river
- timber-framed and corrugated iron clad pump house which predates scout use of area
- a camp fire circle dug into the ground close to the river (c1960)