The weather
Key West has never had a frost. It is the most southern city in the contiguous US and its tropical climes meant President Harry Truman chose the town as the site of his winter White House from 1946 to 1952. It is closer to Havana than Miami — in 1978, Charles McCoy, the mayor of the island, water-skied the 100 miles or so across the Straits of Florida to Cuba.

A fisherman’s paradise
The warm waters between mainland Florida and the Keys are known locally as the “back country”. Anglers can find a wealth of game fish, such as tarpon and permit. In the deep-sea areas off the Keys’ southern coast, where Ernest Hemingway used to take his boat, Pilar, there are bigger fish to fry — marlin worthy of The Old Man and the Sea.

It’s a third of the price of New York
According to Trulia, the real estate website, median home sale values in Key West have increased 8 per cent in the 12 months to August 2017. The average price per square foot is $501. A favourable comparison with New York City — where median home sale prices have fallen only 2 per cent in the year to August, and the price per square foot is around the $1,526 mark — would be an understatement.

Wheels of fortune
As an island town — where petrol can cost over 10 per cent more than in Miami because it must be transported from the mainland, and parking spaces are limited — Key West is a rare spot in America where cars are often considered more effort than they’re worth. Scooters and bicycles rule instead.

Treasure hunting
It was from Key West that Mel Fisher and his “Golden Crew” planned their 16-year hunt for the Nuestra Señora de Atocha, a Spanish ship that sank in 1622. In 1985 they succeeded, making what was then the most valuable shipwreck discovery of all time. They claimed $450m of treasure, including 32kg of emeralds, but much of the Atocha’s cargo is still somewhere on the seabed.

Photographs: Don Emmert/AFP/Getty Images; Getty Images/iStockphoto; Corbis via Getty Images