Seven days in the Florida Keys: a hundred and thirteen miles of road with sea on both sides

The first afternoon does not leave the island and barely leaves ten blocks.

The Art Deco Historic District is about eight hundred buildings from the 1920s to the 1940s in a square mile, the largest concentration of the style anywhere, and it survives because a preservation campaign in the 1970s stopped the lot being knocked down for towers. Walk Ocean Drive, then one block inland on Collins and Washington, where the buildings are less painted and more interesting.

Española Way is two minutes west, a short block built in 1925 as a mock Mediterranean village, pedestrianised and lined with tables under awnings.

Then the beach, which is genuinely enormous: a hundred metres of sand from the dune line to the water, with lifeguard huts in colours that are themselves photographed constantly.

Eat late, because everybody here does, and preferably not on Ocean Drive, where the service charges catch people out.

Cross to the mainland for the day. This is the half of Miami most visitors skip and it is the more interesting half.

Calle Ocho is Southwest 8th Street and the spine of Cuban Miami. Start with a coffee at a walk-up window, then walk: an Art Deco cinema from 1926 that showed subtitled films to newly arrived Cubans learning English, cigar rollers working in shop windows, and a park where men in guayaberas play dominoes competitively and have done for decades.

In the afternoon, fifteen minutes south to Vizcaya, where James Deering built himself a Renaissance villa on Biscayne Bay between 1914 and 1922, filled it with four centuries of European furniture, laid out formal gardens behind it and moored a carved stone barge in the water in front as a breakwater. About a thousand people worked on it in a town of ten thousand.

Back on the beach in the evening, the Wolfsonian is the best museum in Miami and almost nobody goes: a 1920s storage warehouse where wealthy winter residents left their furniture between seasons, now holding the design and propaganda of the industrial age. It opens late on Fridays.

Ten minutes north of it, the Holocaust Memorial is not a museum and takes twenty minutes and is the thing people remember from this city.

A hundred kilometres and about two hours without stopping, which nobody manages. The road leaves the mainland south of Homestead, crosses eighteen miles of mangrove and sawgrass with nothing on either side, and arrives at Key Largo, where the mile markers start counting down.

Stop at Key Largo for the underwater park, which was the first of its kind in the country and protects a stretch of the reef. Glass-bottom boats, snorkelling trips and dives all leave from the same marina, and the two and a half hour snorkel trip is the easiest introduction to the reef on the whole chain.

Islamorada is another thirty minutes south. It is a string of islands rather than a town, with fishing lodges, art galleries in old conch houses and a fair number of pelicans standing on things.

The memorial on the ocean side commemorates the Labor Day hurricane of 1935, which killed several hundred people, most of them First World War veterans working on the highway, and destroyed the railway that ran down these islands. It is a stone plaza with a crypt under it and it takes fifteen minutes.

Then a quarry full of fossil coral, cut for building stone in the 1900s, where the saw marks reveal the cross sections of a reef that grew here 125,000 years ago. Eat on the water and turn in early.

A hundred and twenty-five kilometres to Key West, about two hours without stops and half a day with them. This is the best of the driving.

The Seven Mile Bridge is halfway down and is the one everybody photographs, with the old railway bridge running alongside it, disused and broken in the middle, carrying nothing. A restored section at the northern end is open to walk and cycle and goes out to a small island with a house on it.

Bahia Honda, just past the bridge, has the best beach in the Keys by common consent: real sand rather than rubble, shallow water, and the shattered end of the old railway bridge standing over it.

Key West appears at the end of a causeway in the early afternoon. Check in, leave the car where it is for the next three days, and walk.

Then Mallory Square for sunset, which is an organised event with jugglers, a cat trainer, buskers and a crowd, and has been every evening since the 1960s. It is exactly as touristy as it sounds and everybody goes anyway.

The town day, and everything is within a mile.

The Hemingway house is a Spanish colonial villa with a wraparound veranda where he lived for about a decade in the 1930s and wrote To Have and Have Not and much of the Spanish Civil War material. He kept cats; around fifty of their descendants still live on the grounds and roughly half carry the extra toe. The guided tour is short and included, and the writing studio over the old carriage house is the reason to take it.

Ten minutes away is the Little White House, a naval officers' quarters that Harry Truman used as a working retreat for 175 days across eleven visits, left almost exactly as it was, with the poker table he had built into the sun porch.

In the afternoon, walk to the fort at the western tip. It was begun in 1845, held for the Union through the Civil War in a Confederate state, and the beach in front of it is the best swimming on the island: deep water close in, actual sand, and shade under the Australian pines.

Eat conch fritters somewhere, and take the sunset from the fort rather than the square if you would rather have it quietly.

The water day, and there are two versions of it.

The short one: a snorkelling or diving boat out to the reef, which is six miles offshore here, for a half day. Sailing catamarans do the same trip with lunch and rum on the way back, which is a very Key West way to spend an afternoon.

The long one, and the better one if you can get a seat: the Dry Tortugas, seventy miles west, a cluster of sand islands in open ocean holding Fort Jefferson, an unfinished nineteenth century brick fortress of sixteen million bricks that was used as a prison and is now reachable only by ferry or seaplane. The ferry runs about two and a quarter hours each way, includes lunch and snorkelling gear, sells out weeks ahead, and leaves you four and a half hours on the island. It is the best day trip in Florida.

Whichever you choose, come back in time for the eco-discovery centre by the naval basin, which is free, small and explains the reef, the mangroves and the Everglades system that feeds them better than anything else in the Keys.

Last dinner, and one drink somewhere with a band in it.

Key West has a small airport with connections through Miami, Fort Lauderdale and Tampa, which is the easy exit and usually the expensive one. Driving back to Miami is four hours and worth allowing five.

Before either, take the morning slowly. The wildlife rescue centre near the beach takes in injured birds and has released a couple of thousand of them since 1993, and it costs nothing to walk round.

Then a last swim, a last coffee, and the mile markers counting back up.