Merengue. It's everywhere in the Dominican Republic, more like a rash than music. Yet it is possible in this most beautiful country to hear the sound of whales dancing
Merengue music is the heartbeat of the Dominican Republic: it suits the nature of the place, at once frenetic, irregular and intriguing. It must also be one of the few dance crazes to owe its genesis to a brutal dictator. In the 1930s, Rafael Trujillo adopted this provincial style of song, welded it to his own vicious style of nationalism and promoted it as a national treasure. Trujillo was assassinated in 1961, but his musical legacy has conquered the discos of the world and in his home country it is omnipresent. Every beach-side bar, every hotel, every taxi and every shop fidgets to its non-stop tempo.

The seaside strip in Santo Domingo known as the Malecon is the venue for the national merengue festival every summer. Then, the clamour must be awesome, for the average Sunday-night thrash is raucous enough. As I walked along the broad boulevard, fluorescently lit vehicles pulsed with the bass beat of the car stereos within, while gangly youths sported competing boomboxes all hammering out the ubiquitous rhythm. Preposterously long- legged girls shimmied and swirled, while a succession of gauche suitors tried their luck with ever more extreme gyrations. Not for nothing has the dance been described as attempting to knead chewing gum with your buttocks.

I left the Caribbean and the sea of noise behind and turned inland, up the battlements and through the quiet streets of the old colonial centre. By day, this is the haunt of camera-toting American cruise-trippers, but by night I had the place to myself. The narrow streets and crumbling sandstone alleys had a timeless atmosphere, and I wandered around getting happily lost until late into the night.

The Dominican Republic is extraordinarily diverse - from semi-desert to lush forested mountains, from grandiose mansions to sprawling shanty towns, and from sunbather-packed sands to desolate highways - all in a country smaller than Scotland. It is this unlikely mix that attracts the nosy traveller.

Some of the country's beaches which are never crowded - with good reason - are those of Lake Enriquillo. A hundred or so feet below sea level, in the middle of a parched and barren landscape, the cool, blue waters may look inviting; but the lake is brackish and the only swimmers are the crocodiles that call it home. I left paddling to the flocks of flamingos which made comic and disjointed splashdowns in the shallows.

If wildlife is your reason to visit the Dominican Republic, you shouldn't miss the very different kind of splashdown that takes place off the north- coast town of Samana. Here the creatures trying to take to the air are 50ft long, weigh 40 tonnes, and tend not to fly long distances. Humpback whales are designed for more aquatic pursuits, but that doesn't seem to stop the leaping leviathans, and small boats take enthusiastic whale- watchers into Samana Bay to see these spectacular marine show-offs. Though no one is certain why they jump - to dislodge parasites, as a form of communication, or perhaps just for fun - the sight is awesome. Close up, such strength and grace is humbling.

If further proof of the power of nature was required, it was evident all along the road to La Vega. Hurricane Georges passed this way a year ago, leaving a wake of levelled houses and toppled trees. Lurid splashes of fresh paint revive some hastily repaired dwellings, while other homes are already being reclaimed by the jungle. The centre of the island is a mass of high mountains and fast flowing rivers, an outdoor enthusiast's utopia.

The last bus to the hills had left by the time I arrived in the gateway town of La Vega. Help arrived in the form of an ancient and overstuffed Datsun. These carreras publicos go to places beyond those of the map, at any time of day. They also tend to be full and this one already had seven passengers - in a car meant for four. No matter. My bag was lashed to the roof and I joined the men in the back. The engine coughed thick white smoke, the radio blared merengue. We were off.

The roof seemed to be the only part of the car not entirely composed of iron oxide, so I clung to it until it bent. The road climbed steeply, skirting vertiginous drops and showered by lacy waterfalls, until the patchwork paddy-fields of La Vega Real were far below. Tropical bananas and palm trees gave way to mountain pine and alpine tree ferns, and roadside shrines were acknowledged with a quick prayer-crossing (though I was relieved the driver abstained when driving round the most suicidal corners).

As the dusk turned to purply blackness, we pulled to a halt in Jarabacoa, capital of the mountains. I found a room in a cheap hotel above a combined pool hall, strip joint and - inevitably - disco, and passed a night in fitful slumber. I made an early start in the morning, keen to savour the cool mountain air. The tang of wood-smoke hung in the early mist as I strode down a road everyone had told me was closed.

On my map it traced a thin squiggle through the hills, but the locals claimed that hurricane damage had rendered it impassable. I had my doubts about this and pressed on. For once the air was empty of the sound of music and I had only birdsong to keep me company. It was bliss. A small sign pointed the way to the waterfalls of Salto de Baiguate, and I left the road for a rutted track through fields of sugar-cane and wild, white lilies.

The detour was worth the effort. A thundering torrent crashed into a canyon where dripping orchids festooned the path. A battered pier of sandbags snaked across the river, hinting at a bridge too far. I loitered, revelling in the tranquillity and then slowly made my way back to the road over the mountains. Jeeps passed me every half hour or so, a surprising number for a road supposed to be shut, so when a pick-up truck lumbered past me on a steep gradient I flagged it down.

The truck didn't stop, but the shouts from the cab were all the encouragement I needed to fling myself over the tail-gate and onto the flat bed. I found I had company. Two pigs snorted violently at my rude interruption, then settled back into the serious business of chewing each other's ears.

If the road to Jarabacoa was impressive, this was something else. The track was a rich red, the colour of Accrington brick. It snaked and writhed up a perilous incline, its path the work of some demented Zorro. Great swathes of mountainside were missing, swept away in the hurricane rains, but the road, it seemed, was definitely open.

At length we burst out onto a ridge and skidded to a halt in a precarious hamlet. The porkers squealed, and I was gestured down. For the swine, this was the end of the road; for me, merely the end of the ride. I thanked the farmer, shouldered my pack and began to walk.

It was glorious trekking country. Great blue vistas stretched off to all compass points. Pico Duarte - at more than 10,000ft the highest mountain in the Caribbean - soared out of the jumbled mass of peaks to my right. I passed through tiny tin-roofed villages where pendulous red flowers hung over the road. All too soon, after two hours of hiking, the ridge began to first to sag, then limp and finally descend.

At the end of the road I managed to cadge a ride to Constanza. I walked to my hotel in the chill night air, and caught the drifting sound of merengue coming from a distant bar. The rhythm that had dogged me throughout the country now seemed strangely enticing. The dive was packed, the music loud, the dancers' contortions looked painful, but I think the spirit of the Dominican Republic had finally got my feet tapping.

Getting there: The best way to get there is on a charter flight from the UK; scheduled services are indirect and expensive. Richard Naisby paid pounds 199 for a last-minute seat-only deal. Numerous tour operators offer charters, either on a seat-only basis or as part of a package holiday. These include Airtours (0541 500479), First Choice (0161-745 7000) and Thomson (0990 502580). British visitors will find they must pay $10 to Immigration upon arrival. More information: Dominican Republic Tourist Board, 40 Crawford Street, London W1H 2BB (0171-723 0097)