Key West or St. Augustine?

For a day on the sand, St. Augustine has the better beach. Wide, flat, pale beaches run the length of Anastasia Island, from the dunes of the state park down to quieter Crescent Beach, and they are only a short drive from the old town. The surf is easy and the water shelves gently. The catch is the season: the Atlantic is only warm enough for swimming from late spring to autumn, and it is usually greenish rather than clear.

Key West turns this round. Its town beaches are small, with imported sand at Smathers and coral rubble at Fort Zachary Taylor, and seagrass and seaweed make wading less pleasant. The sea, though, is warm, calm and clear for most of the year, and best for snorkelling. For a classic sandy beach you drive about an hour to Bahia Honda.

Neither town offers much range, and both depend on seafood, but the local flavour is different. Key West looks south to Cuba: pressed Cuban sandwiches and strong coffee in the morning, stone crab and pink shrimp at the dockside shacks, and Key lime pie everywhere.

St. Augustine's own touch comes from its Minorcan settlers. The fiery datil pepper goes into hot sauces, a spicy tomato clam chowder and pilau, and oysters come from the marsh creeks. In both towns the main tourist street, Duval in one and St. George in the other, is where to eat least well.

St. Augustine has far more history to see. Founded in 1565, it has the coquina Castillo de San Marcos on the bayfront and a Spanish quarter of balconied lanes and walled gardens. On top of that sits a Gilded Age layer: Flagler College's Tiffany glass and the Lightner Museum in the old Alcazar Hotel. It rewards a few full days.

Key West's appeal is more about atmosphere than monuments. Its Old Town is a large district of wooden conch cottages and Victorian verandas, and its sights are small and personal: Hemingway's house and cats, Truman's Little White House and the wreckers' treasure museums.

This is where the two differ most. Key West is built for staying out late. Bars on Duval Street stay open into the small hours, you can carry your drink from one open-sided bar to the next, and the upper end of Duval has a long-established gay scene. Fantasy Fest and the winter season are its loudest times.

St. Augustine's evenings are much shorter. There are courtyard pubs and cocktail bars around St. George and Hypolita Streets and a few beach bars on Anastasia Island, but most close well before the small hours. It suits a drink after dinner rather than a big night out.

Key West has the better outdoors, almost all of it at sea. Boats leave daily for the coral of the Florida Reef. The backcountry flats are known for tarpon and bonefish, and the Dry Tortugas offer clear water and serious birdwatching. On land there is almost nothing.

St. Augustine is the better place for walking. Its salt marsh, dunes and hammock forest give you trails in Anastasia State Park and long birding walks in the Guana Tolomato Matanzas reserve. Kayak trips through the creeks often meet dolphins, but there is no reef to match Key West's.

At the end of the Overseas Highway, Key West has one outstanding excursion: the ferry to Fort Jefferson in the Dry Tortugas. Otherwise there is the drive over the Seven Mile Bridge to Marathon's turtle hospital, and Miami is too far for a day.

St. Augustine has a longer list, though you need a car for all of it. Jacksonville's museums and gardens are under an hour away, and Fernandina Beach and Daytona are easy drives. Kennedy Space Center and the Orlando parks are a long but popular day out.

Key West can keep children happy for a few days, and most of the fun is on the water: glass-bottom boats and snorkelling trips over the reef, calm shallows at Fort Zachary Taylor, and in town a small aquarium and a butterfly conservatory. At heart it is an adult island, though. The drinking on Duval Street starts early and Fantasy Fest is firmly for grown-ups, so families need to choose their streets and dates with care.

St. Augustine makes the easier family base. Its pirate and colonial-themed museums turn the town's history into a game, the trolleys spare small legs between sights, and family-style restaurants are everywhere in a compact, safe centre. The main strains are summer heat and crowded pavements at weekends, and for roller coasters it is a two-hour drive to Orlando.

Key West is easier without a car. The whole island is flat and compact, the harbour, bars and sights are all close to Duval Street, and bikes and electric carts are the normal way to get about. You only need wheels to go further up the Keys.

St. Augustine's historic district is just as easy to walk, and the trolleys loop past the main sights. But the beaches, the lighthouse and everything further away are a drive across the bridges, and the local buses are of little use to a visitor.

Neither is a shopping destination. Both have a main street full of T-shirts and novelties, and the better buys are elsewhere: in Key West, Old Town galleries, hand-rolled cigars and sponges from the harbour; in St. Augustine, antique and craft shops on Aviles Street and bottles of datil sauce. Only St. Augustine has an outlet mall for mainstream brands, out by the interstate.

Both are expensive, but Key West is noticeably more so. The island has little room to build, so rooms cost a lot, and the boat trips and ferry that make the stay worthwhile add up fast. Late summer, in the stormy season, is the cheapest time.

St. Augustine is easier on the budget. Chain motels by the highway or on Anastasia Island cut the cost of a room, midweek stays help, and walking the old streets and using the public beaches costs nothing.

There is about as much live performance in both towns, of different kinds. Key West's is informal and theatrical: drag cabaret every night, singer-songwriters in the Duval bars, and jugglers and trained-cat acts at sunset on Mallory Square, plus a small winter symphony season.

St. Augustine's big stage is the open-air Amphitheatre in the woods on Anastasia Island, where touring rock, country and folk acts play for much of the year. For opera or a serious theatre season, you would have to look further afield from either town.

Key West is the better place to unwind, as long as you stay away from Duval. Guesthouses built around pools and gardens, resort spas, easy-to-find yoga and the habit of stopping for sunset make for a slow stay.

St. Augustine has fewer spas and relies more on its pace: B&B verandas, courtyard gardens and an evening walk along the bayfront seawall. Neither has any thermal or bathhouse tradition.