Ursula Andress is to blame. She started it, emerging from the Caribbean and walking to a spot on Dunn's River Beach that I can still see 40 metres behind me. White bikini, black-handled knife, 007's admiring gaze — it's an image that has been scorched onto the retinas of movie-watchers since the first Bond film, Dr No, was released in 1962.
You can probably fill in the next few frames yourself — the meeting with the world's most famous secret agent, the bullets of the eponymous villain's henchmen, the escape up the waterfall that plunges from the beach's rainforest backdrop and foams to a conclusion on the soft sand of this sheltered cove on Jamaica's north coast. A waterfall that, should you have the inclination and nerve, you can climb in real life.
So it's her fault. It's her cinematic footsteps that have led me to this precarious position — wobbling on a slippery boulder, a fifth of the way up this deceptively steep cascade.
But at least I'm not alone. Above me, a family of four is also aiming for the finishing point that waits 950ft upstream. Dad, advancing slowly, is tussling with the obvious problem — that Dunn's River is flowing in one direction as we move in the other. His son, blessed with the fleetness of foot and raw confidence that comes of being (I'm guessing) ten, has no such worries. He leaps between dry patches as if possessed by a mountain goat. I, by contrast, have all the poise of a newborn horse. My legs wobble as I take my next step — and suddenly I'm waist deep. The water is surprisingly cold.
It isn't until I (finally) reach the top that I absorb the prettiness of the picture. Coconut palms whisper and sway. African tulips — fat red flowers — burst forth on the limbs of fountain trees. Turkey vultures wheel in the gaps where the sky peeps through the foliage. If I squint — and block out my fellow clamberers — I can see it as it was, the landscape that greeted Christopher Columbus when he first sighted Jamaica in 1494.
The explorer landed 15 miles west of Dunn's River, at a natural harbour now known as Discovery Bay. And he did, indeed, make quite a discovery on that May morning. Because Jamaica is large. At 4,441 square miles, it is the third biggest island in the Caribbean. Its areas of interest are many: Kingston, the south-coast capital; Negril and Seven Mile Beach in the west; Port Antonio in the east; the Blue Mountains of the interior, jungle-clad in the lofty reaches, pregnant with coffee on their lower flanks.
But since the day Columbus landed, it is the north coast that has issued a siren call to visitors, and the main enticement is clear — the golden powder that runs, in a near unbroken strip, for 130 miles. Luxury hotels nestle in clusters on its shoulder — the towering palaces of the five-mile 'Elegant Corridor' outside Montego Bay, the modern hideaways of Ocho Rios 60 miles east, the small properties between at Runaway Bay. And tourists come in their thousands —sun-seekers, couples, the merrily retired, the family throng.