At about midday, the cloud finally reaches the summit of Piton de la Fournaise - the drop-dead moment in every Réunion island visit. It doesn't build up overhead like it does anywhere else in the world, but creeps up the slopes of the volcanic cone and spills into its crucible through the cracks and gaps in its jagged crown. I'm standing at the Pas de Bellecombe lookout, trying to come to terms with the scale of Piton de la Fournaise, the peak of the furnace, when the giant bowl filling with swirling cloud suddenly looks like a sorbet dish given the high theatre of Heston Blumenthal's dry-ice treatment. Or maybe it's just time for lunch.
It's not just the behaviour of the clouds that is different here from anywhere else in the world. Réunion itself is different. The entire island is shrouded in mystery and intrigue and in an unspoken smugness about its beauty and isolation. In Australia we talk of the tyranny of distance. On Réunion, distance is regarded as protection. Its seclusion protects its diversity and its idiosyncrasy; its uniqueness, its incredible "wow" factor.
Some places achieve an equilibrium by being neither one thing nor another. Réunion is a bit of everything, but in equal parts. It is able to deconstruct its diversity and present it as harmony. So where exactly are we? That's a question I find I'm constantly asking myself during the course of my visit. Clues provide information - and misinformation. The espresso and the two rolls of pain au chocolat were €6.75 - so we're in the Eurozone. When I left her €10, the waitress said, "Merci beaucoup," so we're definitely in French territory. And yet I'm feeling reasonably chirpy after a mere 12-hour flight from Sydney. Réunion is just north of the Tropic of Capricorn and is the only French territory in the southern hemisphere.
Back in the 1960s, when commercial jets opened the skies to the general public, the travel industry's irresistible enticement was, "Be the first on your block to visit…" Well, it's still possible to be the first on your block to visit Réunion island. It is a speck in the heart of the Indian Ocean, 750km from Madagascar, 2000km from the east coast of Africa and more than 9000km from Paris.
The volcanic island - Fournaise is one of the most active volcanoes in the world - extends beyond 2500 square kilometres and rises to a height of more than 3000 metres. France is famously generous with its départements d'outre-mer and has recently built an expressway that makes it possible to drive around the perimeter of the island in five-and-a-half hours. The unique attractions of the island, however, are to be found in the spectacular wildness of its interior where prevailing winds, altitude, topography and rainfall all influence a staggering diversity of landscapes and climates.
The charming idiosyncrasy of this place is one aspect of a colourful Creole culture - the island's rich ethnic mosaic pieced together from European settlers, slaves from East Africa and Madagascar, and, following the abolition of slavery, Tamil Indians from the Malabar Coast, Chinese traders, Muslim Indians from Gujarat, and people from the islands of Comoros and Mayotte. They are components of what today is an exemplary multicultural society exuding tolerance and shared pride. I suspect the high mortality of the slave trade instilled in its survivors a sense of solidarity that provided a good base for a cohesive community.
Arab and Portuguese seafarers knew the island long before a group of mutineers from Madagascar were deported here. After three years, the mutineers returned home in rather good health, alerting the governor of the French settlement of Fort Dauphin of its potential. A ship was sent to take possession of the island on behalf of the king of France and it was named Île Bourbon (after the French royals rather than the whiskey); it was first occupied by French settlers in 1665. The name Réunion dates back to 1793 following the fall of the House of Bourbon and the union of revolutionaries from Marseilles with the National Guard in Paris.
There's idiosyncrasy, too, in the island's physical diversity. It has been said that Réunion offers all the attractions of a whole continent squeezed onto one island. But that doesn't prepare you for the dramatic changes of its scenery. "Just like Switzerland," says our guide, driving through dense pine forests. "Just like Scotland" as we cross moors of stunted growth. And "Just like France" as we descend back onto the Plaine de Cafres where dairy cows graze contentedly behind a tiny shop and café proudly introducing itself as Le Palais de Fromage. Behind the counter, Marie-Sylvie Robert wraps her precious cheeses in waxed paper with the care and precision one might expect at Tiffany & Co. or Cartier.
Rising steeply out of the ocean as it does means Réunion offers a vertical stack of changing landscapes and climates. Locals choose to live at the altitude at which they are most comfortable. Our guide Philippe Techer didn't like the humidity on the coast, so he moved to a house built at an altitude of 500 metres where it was five degrees cooler. Below water level, there's the tropical magic of a coral reef that has created a lagoon 25km long. At 3070 metres, there's the sometimes snow-capped Piton des Neiges. And in between, in the foothills and valleys and high plains, in the crags and cliffs and canyons - Jurassic in their wildness - there are 193 distinct habitats making the island a treasure of natural diversity and a prized UNESCO World Heritage site. Réunion's distinguishing features are its volcanic cones (or pitons), cirques and ramparts. The island's three cirques are vast cliff-ringed basins caused by the land subsiding during volcanic activity, and the ramparts are impressive rock walls which make many areas inaccessible.
Although at least half the island is too rugged for cultivation, the surprisingly high population of more than 800,000 and a population density of more than 300 people per square kilometre makes it one of the most closely packed regions in the European Union. Most people live on the coastal fringe. In the north of the island is the main city, St-Denis, the modern, cosmopolitan home of 130,000 inhabitants. Adjacent St-Marie is home to the main international airport, Roland Garros. To the west are a lively tourist strip and the towns of St-Paul, St-Gilles and St-Leu. The east coast boasts St-Anne, St-Benoit, St-Andre and St-Rose - all sticking their heads above wide plantations of sugarcane and vanilla. And in the rugged, untamed south, the major towns are St-Pierre, St-Joseph and St-Philippe.
"Named after you?" we ask Philippe Techer, our guide. "I would not wish to be a saint," he replies. "Saints only have a past, but sinners have a future."
They certainly had on Réunion, because the interior of the island was largely settled by the esclaves marrons - rebel runaway slaves. Many of the popular hiking tracks we see were once treacherous paths followed by slaves on the run from coffee and sugar plantations to the interior. In fact, until the road was completed in the 1930s, many visitors to the thermal spa town of Cilaos were carried up in sedan chairs.
"Much easier these days," says Techer, accelerating the Peugeot through the first bend of the climb to Cilaos, the most populous of the cirques. A famous 420 bends later, having survived single-lane roads carved out of cliff faces, negotiated sheer drops, passed through tunnels in the rock, and crossed what seemed to be the roof of the world, we're not so sure. Not all those people leaning over the railings beside hastily parked cars are taking in the scenery.
The view over Cilaos is the one that goes close to putting the oft-sighted image of Peru's Machu Picchu in its place. An emerald oasis dotted with pastel-coloured chalets and ringed by brooding purple peaks, it is pure fairytale. Its name is said to derive from a Malagasy word meaning "place you never leave". More than 6000 people live in this enchanted basin, and it's a toss-up as to whether they never leave because of its beauty or because they fear the road being cut off. Cilaos also does its bit to maintain the cultural confusion of Réunion. As I walk down the picturesque main street towards the dazzling white church of Notre-Dame-des-Neiges embossed against the lush green mountainside, I encounter a Chinese shopkeeper listening to AC/DC on an old ghetto-blaster the size of a beer slab. "Bonjour," he says cheerfully. In another of the contradictions of Réunion life, the town is the sunniest and driest of the three cirques, but once received 73 inches of rain in 24 hours.
Despite the profusion of saints on the map, there's a delicious pinch of pagan, a glimmer of voodoo sorcery, even a twinkle of mischief with mainstream religion to be glimpsed when the surface is scratched. Local imagination is still haunted by the past. Pirates were common among the early visitors to Réunion and one of the more colourful was a Captain Olivier Levasseur, executed here in 1730 and buried in the old cemetery overlooking the beach at St-Paul on the west coast. A cult grew up around his promise of buried treasure, and each night bottles of rum, cigarettes and candles are still left on his grave.
Back at the keyboard it proves difficult to conjure an overall impression of Réunion. This is a place of impressions, plural: Marfate's villages, inaccessible by road, meaning some inhabitants have never been to the coast; pretty Hell-Bourg, one of a network of old Creole villages being preserved along with the island's heritage, its pastel-coloured houses putting it on the list of Les Plus Beaux Villages de France. The dramatic drive to Salazie where waterfalls cascade across the road - "Pisse en l'air" says the warning sign, and everyone stops for a photo opportunity, pretending that's what they're doing. The lively and good-natured markets at St-Paul - postcards for the family or another caramelised pork samosa? The samosa wins. The lava road around the south-eastern shores of the island where lava flows from Fournaise have crossed the coastal highway, and months after an eruption the subsoil remains too hot to touch and rain vaporises in clouds of steam. Dining on the beach at the attractive Grand Hôtel du Lagon at St-Gilles-les-Bains. Looking out over the brown volcanic-sand moonscape of Plaine des Sables and trying to explain the sight: "Neil Armstrong," says Techer. "Thelma and Louise," says our photographer. "Mad Max," says another.
Appropriately for such a diverse country the food reflects the terroir. The traditional Creole dish throughout the island is a curry, called the cari, or the carry, and sometimes even the kari. Pronunciation is important but spelling doesn't matter on Réunion, because so many languages have contributed to the local patois. And so we get to rub shoulders with Réunion gastronomic royalty when Henri Romile, "the king of cari", takes centre stage. The Creole inhabitants of the island still prefer to cook over flame and Romile stipulates a fire of cassia wood. The common cookware is the marmite - a large cast-iron casserole as deep as it is wide - and into it go some basic ingredients of the local cuisine: garlic, ginger, turmeric, and the zest of combava, a local kaffir lime. Plus onion, green chillies, diced tomatoes, parsley, coriander, thyme, and loads of freshwater shrimp. It is served with rice and the ubiquitous fiery chilli chutney.
In the higher altitudes of the interior the cari tends to be more rustic: chicken, rabbit or goat served with palm-heart gratin or rice, coconut and choko, the vines of which fill whole valleys. Around the more sophisticated coastal fringe, the food culture is vibrant and cosmopolitan: tandoori fish kebabs with pineapple and coriander, smoked pork strips, vanilla duck, steamed ginger squid, garlic baked crab and ostrich brochette.
But it's the diverse ingredients that go into king Henri's cari that create a striking parallel with Réunion's mixing-pot culture. Different religions, cultures, customs, architecture, languages and cuisines have all gone into the marvellous marmite that is Réunion island. And the memories of the island itself are just as delicious as the memorable meal.