If you’re considering visiting Puerto Rico, watch The Rum Diary, the film adaptation of Hunter S Thompson’s magnificently cynical early novel. Shot on the island (and starring Johnny Depp), it allows you to imagine being among the narrow streets and enjoying the hidden bars of this old, formerly Spanish island.

Before you know it, you’ll have booked a flight on British Airways’ relatively new (and, more importantly, direct) twice-a-week route from Gatwick to Luis Munoz Marin International Airport, located in the Isle Verde section of San Juan, minutes from the Condado area. But don’t go without absorbing a few more details...

San Juan is the meticulously preserved heart of this easy-going Caribbean island. The old town is the pearl of the area, a slice of Andalucian charm transported to the Caribbean. There are streets of beautifully restored houses, many in the Spanish revival style, with shutters and ironwork balconies overlooking quiet courtyards, which call to mind the hidden gems of Seville or Granada. It’s a little bit of Spain and a large dollop of Latin.

Once you’ve worn out some shoe leather on the cobbled streets, take a seat at the bar at La Bombonera, a cafe that’s been dishing out cafes con leche and mallorcas (a divine, buttery sweet bread that’s toasted and sprinkled with sugar) since 1902. Their battered old coffee machine is rumoured to be more than 100 years old, and has seen some service. Regulars (who look as though they might have been around nearly as long) sit under framed sepia prints of old Puerto Rico. It’s an absolute joy.

Take a stroll to La Mallorquina, another characterful and venerable place for lunch. Try bacalhau (salted cod fish) from the specials chalked up by the door while you admire the handsome space and artfully aged mirrors on the walls.

San Juan is big in cruising too – the second largest port in the Western hemisphere with regular visits by all the main cruise lines.

Perhaps by now, you’ve eaten your fill and decided to lay off the rum for a while. What you need is a trip to El Yunque. This mountainous subtropical rainforest (the only rainforest that belongs to the US Forest Service) contains waterfalls, 26 varieties of animal species found nowhere else in the world, panoramic views over the island – and all less than an hour’s drive from San Juan.

For a real change of pace, a short 25-minute hop by light aeroplane brings you to the altogether more tranquil island of Vieques. And what a way to arrive! Travellers who have never flown in an eight-seater, propeller-driven plane before could be forgiven for thinking they had stepped into a Caribbean Bond movie. Isn’t that Roger Moore there on the tarmac in a safari suit?

Vieques is a small island (population: around 10,000; traffic lights: zero) and development is restricted, which means its beaches (pictured) really are unspoilt. This is due at least in part to the fact that, until recently, much of the island was a US military base. Today, much of the land remains sealed off and wild horses roam the roads.

A trip around the island is recommended. Enjoy a fried grouper sandwich at Duffy’s, a supremely relaxed beachfront restaurant at Esperenza, on the south of the island.

A must-see attraction on Vieques is Mosquito Bay, or ‘Bio-Bay’. The waters here are filled with micro-organisms that glow when disturbed. Fish move with astonishing rapidity, leaving glowing trails, and the propellers of the tourist boat cause the water to light up. Combined with a clear, starlit sky, it makes for a truly memorable experience.

If you’re going to enjoy all this, you’ll need somewhere stylish to rest your head.

Weary travellers looking for somewhere convenient and comfortable after a long flight might want to tell their cab driver to make for the Sheraton Puerto Rico. It’s handy for the airport and old town, has fabulous views from the picture windows, and plenty of dining options.

For a touch of style, head to the Caribe Hilton. This is the first Hilton hotel to be built outside the mainland USA, and a treat for fans of the enduringly popular ‘international’ architectural style.

Built in 1949, the Caribe retains some of the glamour of that era. Think of stars such as Gloria Swanson, the Hollywood actress and singer who was one of the first celebrity guests, as you contemplate the sea view from your balcony. It is also said that the Pina Colada was invented here, and the lobby bar is a fine spot to try one of these rum and coconut creations. Do not be put off by the fact that another bar in town makes the very same claim – that’s your cue for some wider rum-based investigating on the island.

Families looking for an all-in-one resort, with everything from a water park to golf course, might want to look at the El Conquistador in the east of the island. This development is seriously large, with a total of 980 rooms and covering 500 acres. It even has its own island, accessible via a ferry service from the resort.

You can advance your education at the classes and seminars the hotel lays on. Thanks to a tasting, I’m now an authority on white, dark and sipping rums.

Travellers looking for a bit of boho luxury might fancy the W Retreat & Spa, which sits on the northern, Atlantic coast of Vieques. It opened just last year, is built from the reclaimed timbers of a former hotel and sits right on the beach. The vibe here is distinctly mellow; there’s no lobby, just a spacious wood-clad ‘living room’. And the villas here are a real treat, with cool tiled floors and acres of space.

Key facts

BEST FOR: Rum, in all its forms, either neat or in the island’s famous cocktails.

NEED TO KNOW: The Pina Colada was invented here.

DON’T MISS: A boat trip on one of the island’s bioluminescent bays.

DON’T FORGET: It’s been a commonwealth of the US since 1917, so you’ll need an appropriate Visa. Spanish and English are the official languages.

Travel facts

Ed Harris was a guest of the Puerto Rico Tourist Board and flew with British Airways, which offers return flights into San Juan, ex-Gatwick from £477 (ba.com).

Operators providing packages include Kenwood Travel, which offers a seven-night, two-centre stay including three nights in Caribe Hilton and four in W Vieques, both on room-only basis and including return BA flights ex-Gatwick and internal flights to Vieques Island, from £1,599. Visit kenwoodtravel.com.

• For more information visit seepuertorico.co.uk.