This 90km walk across the world’s largest sand island reveals a unique and untamed paradise of tropical rainforests, giant sand dunes and crystal blue lakes.

Named K’Gari (paradise) by the region’s Aborigines, Australia’s Fraser Island, the world’s largest sand island is a unique and untamed paradise of tropical rainforests, giant sand dunes and crystal blue lakes.

The Fraser Island Great Walk, which undulates through the island’s interior for 90km, is an excellent way to see many of the island’s best features. The inland vegetation varies from wild heath to wetlands to dense tropical rainforest (it is the only island in the world where rainforest grows on sand); giant sandblows (dunes more than 200m high) form sandy scars that can be seen for kilometres; and at night the Milky Way blazes across the surface of crystalline creeks and freshwater lakes.

Perched lakes
Over hundreds of years, sand drifting off the east coast of mainland Australia formed Fraser Island, a 120km-long largely uninhabited sandbar that is barely 20km at its widest point. The Great Walk starts from Dilli Village in the island’s southeast and passes through open forests and scribbly gum woodlands, full of eucalyptus trees covered in iconic scribbles drawn by burrowing moth larvae. After 2km, take a detour off the track to scramble up the Wongi sandblow for spectacular coastal views.

The trail continues for another 4.2 km to Lake Boomanjin, the world’s largest perched lake (lakes that sit above the level of groundwater and are mostly fed by rainwater), where tannins from the bark of lakeside eucalyptus trees stain the waters reddish-brown. The vegetation changes soon after leaving Boomanjin, with kauri pines, vines and staghorns forming a primeval world after the open woodlands.

Of Fraser Island’s 40 perched lakes, six lie on or close to the Great Walk. The next one you reach, Lake Benaroon, 3.5km from Lake Boomanjin, has delicately-coloured tea-stained water. From here, the next 7.5km begins with a scenic walk along the shore and through low scrub to the soft white sands and blue waters of Lake Birrabeen. Leaving the lake, the trail follows an old logging road through satinay forests (Fraser Island turpentines) and brush box to Central Station, a former forestry camp and now Fraser’s main campground.

Fraser Island’s natural beauty has not always been valued, and a historical cottage near Central Station details the island’s chequered history. A thriving logging industry began in the late 1800s, felling tall kauri pines and satinay trees. The hardwood timber of the satinays was prized by shipbuilders as it is resistant to shipworm, and axe scars are still evident on many of the tall forest trees. Exploitation of the island’s natural resources continued when sand mining began in 1950 to source the island’s rich deposit of minerals such as zircon and monazite. But environmental lobbies brought both industries to an end – sand mining in 1977 and logging in 1991.

A boardwalk along nearby Wanggoolba Creek dives into dense rainforest. The crystalline waters are so clear the sandy creek floor is a pale ribbon, winding around moss-covered rocks, king ferns and piccabeen palms. With a green canopy overhead, hanging vines, tropical foliage and the calls and whistles of unseen forest creatures, it is a world echoing a prehistoric time.

From Central Station there are two ways to reach Lake McKenzie, one of Fraser’s prime sights. Either turn west for a 6.6km hike via Basin Lake, a popular turtle haunt, or turn east for an 11.3km walk to Pile Valley and its impressive stand of satinay trees. Both trails eventually reach Lake McKenzie’s sugar-white sands. The water is a stunning vivid blue, and the pure-silica sand is soft underfoot. The sand is so fine it is ideal for skin exfoliation. The slightly acid water, from decaying plants, limits the viability of aquatic life but in no way affects the pleasure of a well-earned swim.

Valley of the Giants
After leaving Lake McKenzie, the trail heads east for 11.9km, passing through some of the island’s most spectacular open forests and rainforests to Lake Wabby, the deepest lake on Fraser Island at 12m. But a massive sandblow rising from its eastern shore is slowly encroaching on the lake, and within a hundred years will have swallowed it completely. Scrambling up the steep dune is hard work, but the views over the lake and the island are worth the climb.

The longest section of the trail -- 16.2km -- enters the cool, shady forests of the central high dunes. The track follows a blackbutt-forested ridge before descending into a series of corridors between the dunes, where dappled light filters through towering stands of brush box and satinays. Poetically named the Valley of the Giants, this area contains some of the largest trees on Fraser Island. Some are more than 1,200 years old, with trunks more than 4m across. Dwarfed by these giants it is easy to understand Fraser’s appeal to the early logging industry.

Leaving the domain of the forest giants, follow an old tramline for 13.1km to another perched lake, Lake Garawongera. The walk, which passes by the remains of early logging camps, becomes increasingly easier as you follow old forestry trails through open forest and heath land.

The final leg to the eastern beachside village of Happy Valley is a 6.6km (mostly downhill) stroll through open forest and sand dunes. If your sleeping bag has lost its appeal, various accommodation choices from holiday homes to hostel dorms can provide a bed. Sailfish on Fraser has large and comfortable self-contained two-bedroom apartments while Fraser Island Retreat has basic beds and amenities in simple timber cabins.

The Great Walk is best experienced during the drier months from June to September. This is also a prime time to spot migrating humpback whales breaching the waters off the east coast beaches.

The trail has a number of campsites, but camping permits need to be booked in advance. Dingo prints are often found around tents, and bolder animals can be seen on the beach. These feral dogs -- descendents from the Southeast Asian wolf -- climb trees and communicate with wolflike howls. Due to the island’s isolation, Fraser’s dingoes are the most genetically pure strain in Australia, and although small and scrawny, the animals (especially in packs) have been known to attack children and adults. Some campsites are protected with dingo-proof fences, but hikers should be careful. It is illegal to feed the dingoes, or any wildlife, on Fraser Island.