Thanks to Hunter S Thompson, I approach Puerto Rico with trepidation.
The gonzo journalist was here 50 years ago and The Rum Diary, the novel he wrote based on his experience, makes for grim reading as the protagonist, Paul Kemp, discovers an unbearably hot island that is overrun with dogs and has a population that looks like "sick Mexicans".
But maybe the movie version, starring Johnny Depp and released in the United States in October, will have the same beneficial effect on the country that Richard Curtis's film, Notting Hill, had on its titular London suburb?
I suspect not, based on the way Thompson describes the society parties that Kemp finds - populated by "quacks and clowns and philistines with gimp mentalities" - and the restaurants in the capital, San Juan, which will give you "dysentery, gout (and) Hutchinson's disease".
When I arrive, it's in the hope that things have changed since Thompson was here in 1961. I take a taxi to Old San Juan, which Thompson described thus: "The sidewalk was so narrow, it was an effort to stay out of the gutter, and fruit vendors blocked the streets with wooden carts. I walked for 30 minutes peering into foul bars."
But the city I see is charming, clean and peaceful. Certainly there is more than an element of American-style commercialisation - designer shops, boutique hotels, fancy restaurants, souvenir stalls - but there are no foul bars, or for that matter, fruit carts.
Instead there are rangy men selling homemade coconut sorbet from battered carts, salsa dancing in the streets down by the Plaza de Colon on a Saturday night, dozens of pleasant museums and galleries, and a towering 16th century cathedral that contains the remains of Juan Ponce de Leon, who founded the first Spanish settlement on the island in 1508.
There are fat 12-centimetre-long caterpillars congregating on the frangipani trees, waiting their turn to emerge as monarch butterflies, and, underfoot, there is my all-time favourite flora, mimosa pudica, a type of fern that recoils when you touch it. Pudica, charmingly, means shy or bashful.
I have lunch at La Jibarito, a place with Formica tables and a canteen feel. I gulp down camarones al ajillo, amarillos fritos (fried sweet plantain) and mashed casaba. It is all pretty good, except for the mofongo, a dish for which I simply cannot gather any enthusiasm, even though it appears on almost every Puerto Rican menu. Made of mashed roots of one kind or another, in this case yucca, it tastes uncomfortably similar to what I'd imagine unset cement must be like.
Afterwards I visit the oldest coffee shop in the city, La Bomboneria, where all the (male) serving staff look like raddled gangsters, and the bar is dominated by a giant coffee machine that resembles something from Willy Wonka and the Chocolate Factory. The coffee (Puerto Rico grows its own) is strong and pungent, and the casita (local pastry) sticky, crumbly and sweet.
Before returning to the hotel I sit on a bench at one of the main squares, the Plaza Quinto Centenario, where I am confronted by a most peculiar vision: a tiny man, barely 150cm tall, wearing braces, false eyelashes and pegged trousers and with his face painted white like a mime, is reciting tourist timetables, as well as the occasional poem, from the stage in a barely comprehensible Spanish dialect. He takes time out to hug and kiss the locals before he returns to his impromptu show, which is more like a spontaneous act of idiosyncratic joie de vivre than a planned performance.
Later that night I wander streets that seem largely deserted even though it is a Saturday night. I find the locals in Callejon de la Tanca, a few hundred metres from the main square, where old women with the faces of seasoned wrestlers play mah-jong and shriek with laughter while salsa music issues from an adjacent open-fronted bar. The women chew on massive skewers of meat from a street barbecue emitting pungent aromas, while a solitary man in army fatigues has a drink at the bar. It is a scene that might not have changed since Hunter S Thompson was here.
The next day I drive out to the rainforest at El Yunque to the east of the island. The motorway is punctuated with Burger King and Kentucky Fried Chicken signs, but on the way I stop at the big public beach at Suarez and find a row of old beach restaurants painted bright pastel shades and populated by peaceful locals. I eat taco de camarones and bacalaitos in perfect peace, the sound of the waves singing in the distance. The American commercialisation that Thompson feared when he wrote The Rum Diary has certainly achieved a presence, but there are plenty of places to escape it.
At El Yunque, I am confronted with a spectacular feast of concentrated shades of green and brown. I take a 45-minute hike through lush trees; giant snails hang from their bark like pendulous ornaments. At El Menor waterfall I have a chance to swim in a pool at the bottom of a curtain of cascading water. Then I drive to Luquillo Beach, the local surfers' paradise. On the way I pass a crocodile of cyclists following a lead rider who has improbably and precariously rigged his ancient bike with six giant speakers that play Salsa - a Pied Piper taking a day trip in the sun.
Of all the places Thompson writes about in The Rum Diary, his favourite is Vieques Island. He is sent there by a hotel developer to scope out the area and write a piece that will help sell hotel lots, and he is struck by guilt: "I was being paid $25 a day to ruin the only place I'd ever felt a sense of peace." Today, the island remains resolutely unruined.
I stop to pick quenepa fruit from trees on my way to Hacienda Tamarindo, which is small and full of character, festooned with old posters and lovely antiques. A giant mimosa tree grows through the lobby and out of the roof.
That evening I swim in a bioluminescent bay, and watch ancient microorganisms light up like tiny aquatic glow-worms as I flail my arms. I lie on my back in the bathtub-warm water and stare at the stars, sublimely content. "The moment I saw it," wrote Thompson, talking of the south side of Vieques Island where we are staying, "I felt this was the place I had been looking for." I feel the same.
Next day, I return to the main island and drive down to Ponce on the south coast, where I stay in the entirely unspoilt and charmingly faded luxury of the Hotel Melia. My balcony overlooks the Plaza Las Delicias with its ficus trees, fountain and the red and black edifice of the Parque de Bombas, a striking 19th century wooden fire station that is now a museum.
I visit the elegant Ponce art museum, which has an unexpectedly wonderful collection of English Pre-Raphaelite art, then enjoy a guanabana "sour juice" ice cream from King's Cream, which is startlingly fresh and creamy.
On my final night in San Juan, I check into the Caribe Hilton, where Puerto Rico's tourist trade was practically invented in the 1950s. As Thompson wrote, "before Hilton there was nothing. Now the sky was the limit". I drink a pina colada, which was invented in this very hotel, then take a stroll down to La Concha casino, which, according to Thompson, was "a sort of dull frenzy, like taking a pep pill when all you really want to do is sleep". In fact, it is bright and lively and rather fun.
It takes more than a few souvenir shops and fancy hotels to ruin a place like this. If you want to know about today's Puerto Rico, The Rum Diary is a very poor guide. The beaches, the rainforest, the colonial architecture and the bioluminescent bays speak louder than any book or film - and they speak not in prose, but pure poetry.