Washpool's rainforests are survivors from the age when Australia, South America, Africa, India and Antarctica were still joined as Gondwana. As that ancient landmass broke apart and Australia drifted into long dryness, these cool, wet, sheltered gullies held on, preserving plant lineages found almost nowhere else. The park's Willowie Scrub contains the largest intact coachwood rainforest on Earth, and among the canopy stand extraordinary specimens of giant red cedar, the prized timber that once drew axemen across the colony. UNESCO recognised what survives here in 1986, inscribing Washpool and the neighbouring Gibraltar Range within the Gondwana Rainforests of Australia World Heritage Area; the listing was added to Australia's National Heritage List in 2007. To walk here is to walk through deep time.

Long before any conservation map was drawn, this was - and remains - Aboriginal country. Washpool lies on the traditional lands of the Bundjalung, Gumbaynggirr and Ngarabal peoples, who lived in and cared for this landscape for thousands of years. The forests and creeks provided food, medicinal plants, and the materials for tools and shelter, and the knowledge of how to manage this place, including the careful use of fire, was carried across countless generations. The plateau and its gullies were never empty wilderness waiting to be discovered; they were a known, named and tended homeland, and the deep human history here is as much a part of Washpool's significance as its rare trees.

Washpool nearly did not survive into the present. Red cedar had drawn timber-cutters into these ranges since the 1800s, and by the late 1970s a highly mechanised forestry industry had the last great stands of the Viper and Willowie Scrub in its sights. Conservationists fought back, and the campaign to protect these forests became part of a much larger battle over the future of New South Wales rainforest. The park was finally gazetted in 1983 after surveys confirmed it held species found nowhere else in the state, or nowhere else protected. What might have become sawn timber instead became one of the most important rainforest reserves in the country - a rescue measured now in centuries of forest life rather than board-feet.

The biodiversity here is staggering. More than 878 species of vascular plants grow in the park, from 138 families, of which 81 are of conservation significance. The birdlife alone justifies the trip: the superb lyrebird and the rare rufous scrubbird perform in the understorey alongside parrots and honeyeaters. In the leaf litter and creeks live the eastern water dragon and the endangered Fleay's barred frog, while the park's clean waterways shelter the critically endangered eastern freshwater cod. Walkers can sample it gently on the 1.4 km Coombadjha Nature Stroll, immerse fully on the 8.5 km Washpool Walking Track through ancient rainforest and waterfalls, or commit to the 45 km Gibraltar-Washpool World Heritage Walk across both parks. Wallabies, goannas and echidnas turn up along the way - a cast of Australian originals in a forest older than the country itself.