Scenically, so the guidebooks tell us, the best way to get there is to drive down US1 across the causeways that link the Keys with the Florida mainland. But going by air on the propeller-engined, toy-sized plane from Miami has the advantage of preparing you to downsize your expectations.
Once there, we were sharing a three-bedroomed rented house with American friends in the old part of the city, close to the Shrimp Docks where the fishing boats are based. At the back was a small heated pool, shaded by coconut palms; it was January but in the middle of the day the air temperature topped 80F. Key West is the only US city that never gets frost.
On our first morning we started by renting bikes. There were no hills and nothing was very far from anything else. The streets were narrow and renting a car seemed a waste, as well as being anti-social.
Bikes can cost up to $7 a day but there are smaller places that will do them for less and at one of these we negotiated a fee of $28 per bike for six days. They came with heavy locks and the instruction that we always secure them to a sturdy piece of street furniture. Non-returned machines are charged at $100 each.
Thus equipped, we cruised at a measured pace around the streets, perhaps the safest in the world for cyclists. Car drivers invariably give way courteously to wobbly pedallers; fortunately, because it was a few years since some of us had used this form of transport.
The streets are lined with low houses, lush tropical foliage and occasionally quirky shops: one delightful bookshop, Miss Marple's Parlour, sells nothing but crime novels. Few buildings date from earlier than 1886, the year of the second of Key West's two devastating fires, yet nearly all of them conform to the familiar clapboard style of American coastal towns, with front porches and sometimes wrought iron balconies.
House-visiting is one of the attractions of Key West. Its sense of remoteness has long appealed to authors and artists, Ernest Hemingway among them. In 1931 he and his wife Pauline moved into a large and unusual 1851 mansard- roofed house that had survived the fire. To Have and To Have Not is set here, and The Old Man and the Sea is based on his game-fishing exploits in the seas beyond.
The Hemingway house tour is deservedly popular and there is one every 15 minutes, so you seldom have to wait. Guides in Bermuda shorts and pony- tails (tips encouraged) show you around and tell the tale of the large concrete swimming pool, which Pauline had installed as a surprise for Ernest only to find that he resented the expense. They were divorced not long afterwards.
The garden is inhabited by scores of cats, some with six toes - a peculiar deformity inherited from Hemingway's time. Cat souvenirs abound in the gift shop, although in reality he never seems to have kept more than two cats in this house. It was in Cuba, where he moved with Martha Gellhorn after divorcing Pauline, that he had about 50 of them.
Hemingway was as famous for drinking as writing, and the guides try to keep up the legend. Just after breakfast on the morning after our house tour we recognised our guide slipping out of a bar, face glowing and no doubt well fortified for another day of coping with the likes of us.
Several bars in the city vie for the reputation of being the place where Hemingway hung out. Sloppy Joe's is the most celebrated but it is no longer on its original spot. In 1937 it moved a few hundred yards to Duval Street, the city's most lively artery. There is still a bar - Captain Tony's - at the old location, and this was where the writer first met Martha Gellhorn.
Do not go to Sloppy Joe's expecting a Hemingway experience, with sea dogs telling tales of doughty confrontations with giant barracuda. Even if they did you would not hear them, because most evenings the place is packed with young people listening to the rock band on stage. For more authentic local colour, you will do better at the louche places nearer the harbour; the Hog's Breath, Rumrunners and the Schooner Wharf.
Other houses are worth visiting. President Truman enjoyed coming here to play poker and escape from Washington. The officer's mess at the naval base was converted to a holiday White House and has now been restored as it was in the 1940s and 1950s, with Truman memorabilia explained by another team of laid-back guides.
When indoor activities pall, there are many other ways of enjoying the sea in Key West. The beaches, mainly on the south side, are covered with sand regularly brought in by truck. They are better for lounging than bathing, because if you go into the water you have to wear sandals as protection against the coral underfoot.
Our more sedentary party went out for half a day with Captain Vicki Impallomeni, a feisty seawoman who knows where the dolphins are playing and the snapper are biting. When we reached the dolphin area she put some Mozart on the boat's sound system and soon had the appealing creatures doing minuets around us. We peered into a mangrove swamp before catching easily enough fish for our supper. The four-hour trip cost $300 for six of us.
A longer voyage is on the Yankee Freedom ferry to the Dry Tortuga Islands, 70 miles west. The boat leaves Key West at 8am and returns at 7pm, with a stop for a swim and a picnic lunch at Fort Jefferson, a hexagonal island fort begun in 1846 and used as a military prison in the Civil War. There are many rare sea birds to look out for, as well as the turtles that give the islands their name. The trip costs $79 for adults, $49 for children, $69 for seniors. (There are also excursions to the Tortugas by seaplane.)
Several boats take visitors out to see the sun setting: a spectacular show when the weather conditions are right. There are a number of land- borne ways of enjoying it, too. Every evening, crowds gather in Mallory Square, just by the shore and with a great view to the west. Street entertainers eat fire and make pigs do tricks as the crowd waits for the hallowed event. A more comfortable if less atmospheric way of watching the sunset is from the rooftop bar of the Holiday Inn on Duval Street.
There are so many good restaurants in Key West that it is impossible to visit them all in a week. In the high season (essentially the winter months) reservations are necessary almost everywhere, and there can be long queues at places that do not accept them. As you would expect, the seafood is terrific. Of the upmarket restaurants we tried, the best were the Marquess, Trattoria Venezia and Cafe Sole: the bill for dinner customarily came to about $100 for two, including wine and tip. The Half-shell Raw Bar, a barn of a place with long communal tables and beer in plastic beakers, has good fresh seafood, a lively atmosphere, and a bill of only $40 for two.
For lunch al fresco, easily the best place (and the only one we went to twice) is Louie's Back Yard, with a bar and terrace on the beach behind a lovely old mansion. Kelly's is located in the original Pan American air terminal, where planes used to leave for the 90-mile flight to Cuba. On the walls are pictures of 1920s aviation.
Pepe's, by the harbour, is more modest, but does a good breakfast, On our last day we had a splendid lunch at Blue Heaven, in the Bahamian district of town. Caribbean-style dishes are served in the yard at the back, with chickens scurrying around your feet.
Locals say that much of the credit for the conservation of Key West, and for opening some of its its eating places, goes to the gay community, which exerts at least as powerful an influence here as in San Francisco. Whoever is responsible, I hope they keep up the good work.
key west fact file
Trailfinders (tel. 0171 937 5400) offer return flights to Miami from London Heathrow for pounds 274 (incl. tax). They are also able to offer the onward hop from Miami to Key West for just pounds 91.20 (incl. tax) return.
The house rental was arranged through Rent Key West (tel. 001 305 292 9508). Houses vary in price, but our one-third share of a week's rental on this one, in high season, came to $900. For other reservations and information ring the tourist bureau on 001 305 296 7753, or fax 296 6291. It has a web site at wvw.fla-keys.com