What's a good 3-day itinerary for Key West?

Key West is 4 miles long and 1.5 miles wide. You can walk the entire Old Town core in 40 minutes, which means three days here covers the island without needing a car. Day 1 stays south of Truman Avenue. Get to the Southernmost Point buoy on Whitehead Street before 8 AM, when you'll have the concrete marker mostly to yourself. By 9:30, cruise ship passengers line up 30 deep for the same photo. The Ernest Hemingway House at 907 Whitehead Street opens at 9 AM, and the 30-minute guided tour through the 1851 Spanish Colonial building is worth the $18 ticket for the polydactyl cats alone. They sleep on the furniture. Lunch at El Siboney on Catherine Street runs about $14 for a pressed Cuban sandwich with black beans and yellow rice, the warm bread cracking under your thumb. Humidity here sits around 80% year-round, so pace yourself. Walk north along Duval toward Mallory Square by 6 PM for the nightly sunset gathering, where fire-eaters and food carts set up along the pier.

Day 2 moves west into the Truman Annex. The Harry S. Truman Little White House at 111 Front Street opens at 9 AM. Truman spent 175 days here across 11 visits between 1946 and 1952, and the 45-minute guided tour still has his card table and upright piano arranged where he left them. Walk 10 minutes south to Fort Zachary Taylor Historic State Park, built in 1845 and still holding the largest collection of Civil War cannons in the country. The beach here is the best on the island. The water runs clearer than the public beaches, the sand is less packed, and Australian pines throw real shade along the shore. Pedestrian entry costs $2.50. Spend the afternoon swimming, then walk back through the Annex gates by 4 PM to the Mel Fisher Maritime Heritage Museum on Greene Street. The $18 admission puts you face-to-face with gold bars and emeralds pulled from the 1622 wreck of the Atocha. Dinner at Blue Heaven in Bahama Village starts at 6 PM. Order the lobster Benedict if it's available. Roosters will pace under your table. That's part of it.

Day 3 goes north and gets wet. Start at the Key West Butterfly and Nature Conservatory on Duval Street at 10 AM, where $15 puts you inside a glass-domed garden with about 50 butterfly species and a few flamingos in warm, still air that smells like jasmine and wet soil. It takes 30 to 40 minutes. Two blocks north, the Key West Aquarium at 1 Whitehead Street opened in 1934 as one of the first open-air aquariums in the United States. The shark-and-ray touch tank is better than it sounds. Lunch at Pepe's Cafe on Caroline Street, which has been serving since 1909, then a half-day kayak or snorkel trip from the Historic Seaport at 1:30 PM. Most outfitters run 3-hour tours to the mangrove flats or the reef for $50 to $70 per person. You'll likely see nurse sharks, barracuda, and sea turtles if the water is calm. Return by 5 PM and follow the shoreline path east to the African Cemetery at Higgs Beach, a memorial marking the burial site of 295 Africans who died after rescue from slave ships in 1860.

A note on September. You're visiting in peak hurricane season, and afternoon thunderstorms tend to arrive by 3 PM most days. The current heat index sits near 32 degrees Celsius. Start your mornings early, take a long midday break at the hotel pool or an air-conditioned bar, and save outdoor plans for late afternoon. Key West rates 9 out of 10 for LGBTQ+ friendliness (sourced from TTDI's editorial rubric). Solo-traveler safety scores 7.2 out of 10 (see the TTDI Solo-Safety Index). Duval Street gets loud after 10 PM, so if you want sleep, book south of Truman Avenue or in Bahama Village. The entire three days covers about 18 km on foot, with no single stretch longer than 2 km.