Derby, Australia

With a length of 123km, Fraser Island is the world's largest sand island, but this dry fact does little to prepare you for the experience. Accumulated from sediments swept north from New South Wales over the last two million years, the scenery ranges from silent forests and beaches sculpted by wind and surf to crystal-clear streams and dark, tannin-stained lakes. The east coast forms a ninety-kilometre razor-edge from which Fraser's tremendous scale can be absorbed as you travel its length; with the sea as a constant, the dunes along the edge seem to evolve before your eyes – in places low and soft, elsewhere hard and worn into intriguing canyons. By contrast, slower progress through the forests of the island's interior creates more subtle impressions of its age and permanence – a primal world predating European settlement – brought into question only when the view opens suddenly onto a lake or a bald blow. In 1992, the entire island was recognized as a UNESCO World Heritage Site, with all but a few pockets of freehold land and the tiny township of Eurong being national park.

Once on the island, there are a couple of safety points to bear in mind. As there have never been domestic dogs on the island, Fraser's dingoes are considered to be Australia's purest strain, and they used to be a common sight. After one killed a child in 2000, however, dingoes which frequented public areas were culled and you'll probably not see many. If you do encounter some, keep your distance, back off rather than run if approached, and – despite their misleadingly scrawny appearance – don't feed them, as it's the expectation of hand-outs which makes them aggressive. You should also be aware that sharks and severe currents make Fraser a dangerous place to get in the sea; if you want to swim, stick to the freshwater lakes. Lastly, pack some powerful insect repellent.