What is it?

Christmas Island is a speck of ancient limestone and rainforest rising abruptly from the Indian Ocean — an Australian territory so remote and so biologically strange that David Attenborough called its red crab migration one of the greatest natural wonders on Earth. For a few weeks each year, after the first rains of the wet season, some 50 million crimson land crabs pour out of the jungle and march to the sea in a slow-moving scarlet tide, carpeting roads, gardens, cliffs and beaches while rangers close highways and build crab bridges to let them pass. Beyond the crabs, two-thirds of the island is national park: dripping rainforest full of towering coconut-clawed robber crabs, cliffs where golden bosunbirds wheel on updraughts, blowholes that boom and spray like geysers, and the Dales, where freshwater cascades over roots into the sea. The island's 1,700 residents are a warm mix of Malay, Chinese and Australian heritage, and the smell of nasi lemak and the sight of a Taoist temple beside a shuttered phosphate mine tell the story of a century of labour migration. Underwater, sheer drop-offs plunge thousands of metres just metres from shore, and whale sharks glide in to feed on crab spawn — a place where the wilderness genuinely outnumbers the people.

Where is it?

Christmas Island lies in the Indian Ocean about 1,550 km northwest of mainland Australia and just 350 km south of Java, Indonesia, reached by direct flights from Perth (around four hours) and occasional services from Jakarta and Cocos (Keeling) Islands. Base yourself in Flying Fish Cove or The Settlement, and explore the Dales, Hugh's Dale waterfall, the Blowholes, Margaret Knoll lookout, Lily Beach and Dolly Beach by 4WD. The red crab migration usually begins with the wet-season rains between late October and December (timing tied to the lunar cycle, so dates shift each year), while whale sharks appear roughly November to April and the drier months from May to September offer the calmest diving and hiking conditions.

What makes it worth it?

Standing on a road that has been closed not for traffic but for crabs — hearing the faint, papery rustle of millions of legs moving through leaf litter — rearranges your sense of who owns the planet. Visitors describe it as "like walking on another world" and "the most alive place I've ever been", and many say the sheer scale of the migration left them unexpectedly emotional, laughing and tiptoeing at the same time to avoid stepping on a single crab. Because so few travellers make the journey, you often experience it almost alone: no crowds, no viewing platforms, just you, a park ranger's tip and a jungle track. Add in birdwatching that ticks off species found nowhere else on Earth, snorkelling straight off a beach into water 40 metres deep, and evenings eating laksa while flying foxes cross a pink sky, and the island becomes the kind of place you talk about for decades. Years later you'll remember the crab bridges arcing over the highway, the boom of the Blowholes, and the strange privilege of visiting somewhere that feels genuinely, defiantly wild.

How accessible is it?

Getting there is the hard part: flights from Perth run only a few times a week and typically cost AUD 800–1,500 return, and because the island receives just a few thousand visitors a year, accommodation (a handful of lodges, apartments and the resort) and hire cars sell out months ahead — especially during peak crab season. Budget roughly AUD 250–450 per day for a room, 4WD hire (essential for the national park's rough tracks) and food, which is pricier than the mainland because almost everything arrives by ship. Physically it's flexible: watching the migration requires nothing more than patience and closed shoes, while trails like the Dales boardwalk or the descent to Dolly Beach involve moderate walking on slippery limestone and roots. Australian visa rules apply, since Christmas Island is Australian territory, and some national park areas require permits or ranger-guided access — check with Parks Australia before you go. Bring reef-safe sunscreen, insect repellent, sturdy footwear, snorkel gear if you're fussy, and cash-backup, though card payment is widely accepted; there is medical care on the island but no decompression chamber, so divers should be conservative.