Unlike its popular, rum-soaked neighbours St Lucia and Antigua, Dominica is one of the least touristy islands in the region. It has such a delicate eco-system that high-rise hotels and beach-side resorts are impossible to build. The only way to get there, apart from sailing, is to take a wobbly light aircraft from one of the larger islands. Once I had boarded at Guadeloupe, and been asked to close the door behind me, we skimmed the sea for about 20 terrifying minutes before landing, at a perilously steep angle on a tiny airstrip just outside the capital, Roseau.
Even before we had landed, it was obvious that Dominica is not your run-of-the-mill Caribbean holiday destination. From the tiny window of the plane, I could see lush, forested mountains rising sheer into the sky from the thin strip of volcanic beaches that hug the coast. Fishing villages are dotted around them; mango groves and banana plantations creep up the hills, and women wash clothes in the rivers that criss-cross the island. (There are 365 - "one for each day of the year".) "Welcome to Nature Island," said the pilot as we hit the ground.
Alongside Belize, Dominica is rapidly becoming one of the eco-tourist's essential destinations, and not just for being the best preserved oceanic rainforest in the hemisphere. It is entirely volcanic, and each volcano is piled on top of the other to form a backbone of mountains which rise as high as 5,000ft. Trade winds come in from the east across the Atlantic, laden with moisture, and when they crash into this wall of mountains, they shed their load. So, at only 30 miles long, the island boasts vast tracts of rainforest, spectacular waterfalls and tropical vegetation, in addition to the occasional shower.
At Roseau, I hired a sturdy jeep for the half-hour drive down to Soufriere, a tiny fishing village down in the south. Just outside it lies Petit Coulibri, an old 330-acre lime and aloe plantation which has been converted into guest houses. The two-mile track leading to it is a hazardous drive, winding across rocks and rotting vegetation. It goes through abandoned plantations and the ruins of another old estate, once owned by Rose Company, when Dominica was the largest exporter of limes in the world. Its great house is still intact, with beehives and lime presses rusting in the heat. The road was impossibly bumpy, with tree roots like climbing frames straddling the road, giant banana leaves flapping overhead, ferns sprouting from their trunks and goats nuzzling at bushes. The smell of rotting limes is pungent. But Petit Coulibri is well worth the effort. Instead of a fourth wall, my cabin opened on to a balcony that was framed with a canopy of lime and breadfruit trees that gradually gave way to the sea, and Martinique was on the horizon. That night, too exhausted to drive back down to the village, I watched a ferocious storm sweep past Martinique, cross the sea on to land, bending trees double in its wake, and drenching the balcony.
When it had passed, there was a moment's silence, then the sounds of the forest resumed, as anxious crapauds (mountain frogs the size of chickens), sugar birds, bananaquits and solitaires sought out each other's reassuring presence. The next morning they ate my breakfast, which I'd carelessly left uncovered on the balcony.
Soufriere is so relaxed that, after one day, I was on first-name terms with everyone. In the baking-hot afternoon, I watched men play dominoes in the street and women sitting and chatting on their doorsteps. At sunrise and sunset, fishermen haul in their catch, blow conches and sell flying fish, squid and dorado (a kind of tuna) on the beach. At the Seabird Cafe just along the coastal road, I ate it, marinated in lime and chilli and lightly grilled.
But, as well as being a loafer's dream, Dominica is the international diver's best-kept secret. Bobby-John (gold teeth and beaded dreadlocks) took me, equipped with my snorkel, and some serious-looking, rubber-suited divers, out on his boat. The island shelves so steeply into the sea that coral has grown on volcanic outcrops like icing on a cake. Leather-backed turtles and fish of every colour nibble at the beribboned reefs. And further along the Soufriere Bay is Champagne Reef, where I swam through the bubbles of underwater hot springs. I was there at the wrong time of year to go whale-watching, but I did happen to see a school of squid as they cruised past in crocodile formation.
Overground, one of the most spectacular sights is in Roseau Valley: Trafalgar Falls, which actually consists of two waterfalls, Mama (the smaller one) and Papa, which plunges down a 60-metre rockface. I climbed across the slippery rocky ridge that separates them, wading through pools and scrambling over tree roots, and at the bottom of each fall found two naturally formed pools. Mama's was a cold freshwater basin, and Papa's a hot sulphur bath. The route to the 60-yard-wide Boiling Lake - the largest active fumarole or volcanic basin in the world - is a different matter: it's one of the toughest trails on the island. I'd been tipped off to ask for a guide called Antonio who led tours from Titou Gorge, a swim-in cave and underwater mini-waterfall. I was told he had very few teeth and a mass of matted dreadlocks. He was easy to spot. He told me his friends called him Beetlejuice. "They won't tell me why," he added.
Beetlejuice took me through dense jungle to the eerie Valley of Desolation. It took three hours of serious hiking. Mosses and creepers run riot across the track, and aerial roots as tangled as Beetlejuice's dreads (both handy for grabbing on to) brush your face. We climbed the peaks of extinct volcanoes, waded through rushing streams and tiptoed along narrow, vertiginous ridges.
Beetlejuice, like all good Dominican guides, had learnt as a child the names and uses of every plant, bird and tree in the forest. But nothing could prepare me for the Valley. In 1880 a volcanic eruption left this previously forested tract of land a seething mass of sulphuric vents and molten lava. Fumaroles burp up putrid gusts of hydrogen sulphide, and the sun, denied access to the rest of the forest floor, scorches the land. In the rest of the forest, the mud (and there's lots of it) is a delicious, tangerine red colour, and cool to the touch; here it was a gurgling, grey soup.
Just beyond the valley was the famous crater. I peeked over the edge and saw a vast expanse of steaming water. The volcanic heat keeps it simmering at a constant 920C and exuding huge, gaseous clouds.
After all that nature, Roseau was a metropolitan retreat, entirely constructed from pastel-coloured stone and wood. Each house is decorated with gingerbread fretwork and French colonial-style jalousied windows and balconies. The bars are friendly and, in the Botanical Gardens, I sat and watched a cricket match - the men in pristine whites played in a field bordered by towering yam yam and banana trees. At Roseau Museum, set up three years ago by local historian Lennox Honeychurch, I learnt about the island's geological history. Lennox is so well known throughout the island that once, when he was sitting in a bar with an island-hopping Mick Jagger, a customer asked the barman, "Is that Mick Jagger?" and the barman replied: "No man, that's Lennox Honeychurch. Everyone knows that."
The museum displays relics from the island's pre-Columbian past: stone tools belonging to the Arawak tribe (who were driven out by the Caribs) and the grinders and graters they used to break down cassava flour, calabash, aphrodisiacs and narcotics (but Beetlejuice had already told me about those).
Lennox told me what lies ahead for Dominica. Of the two plates that form the Lesser Antilles, Dominica lies on the younger one, which is about 26 million years old. The older is 50 million years old, and time has worn it down to white sand and coral reefs, the "Club Med territory" of northern St Lucia and Antigua. So Dominica's sulphur springs and boiling lakes are running out of time. Give it 25 million years, he said, and the plate will have worn down to the right level for Dominica to be covered with white-sand beaches. In the meantime, the gentle pace of rural life and the secret bounty of its rainforests make for a different kind of holiday.
The author travelled from France to Guadeloupe as a guest of Air Outre Mer, and from Guadeloupe to Dominica on the Inter-Caribbean airline, LIAT (tel: 0181-571 7553). The return journey was via St Lucia on Caledonian Airways. BWIA (tel: 0171-745 1100) is offering flights to Dominica via Antigua for pounds 461.20 per person, including taxes, until the end of November. The price includes a transfer to Dominica on LIAT.
Where to stay
In Dominica, the author stayed at the Petit Coulibri hotel in Roseau. Seligo features the Petit Coulibri in its worldwide brochure with room- only accommodation from pounds 39 per person per night. Seligo (tel: 0121 683 0001). Discovery Initiatives, the conservation-based tour operator, offers one or two-week trips to Dominica, which include the services of walking guide Ken Dill. Prices start from pounds 65 per person, not including flights, and the money goes towards a cross-island hiking trail - the Wai'tukubuli Trail project. Call for more information (tel: 0171-229 9881).
The Dominica tourist office is in Paris (tel: 00 33 1 53424115). For general information about the Caribbean, contact the Caribbean Tourism Organisation (tel: 0171-222 4335).