What's a good 3-day itinerary for Boston?

Three days, three neighborhoods. Day 1 is the Freedom Trail and North End on foot. Start at Boston Common by 8:30 AM, when the grass is still damp and the Common is quiet. Boston Common dates to 1634, the oldest public park in the country. Follow the red-painted Freedom Trail line north through the Granary Burying Ground, where Paul Revere and Samuel Adams are buried three rows apart, to Faneuil Hall by 10 AM. Skip the Faneuil Hall food court. The lobster rolls there are reheated and run $25 for something you'll regret. Walk 10 minutes north into the North End instead. Get a chicken parm sub at Monica's Mercato on Salem Street for $14, or queue at Galleria Umberto on Hanover Street before they sell out around 1 PM. The whole block smells like garlic and fresh bread at noon. Paul Revere House on North Square takes 30 minutes, costs $6. End at Commercial Wharf, where the harbor breeze drops the temperature and you can hear the ferry horns from Long Wharf.

Day 2 moves west to Fenway and Back Bay. Take the Green Line E branch to the Museum of Fine Arts at 10 AM. The MFA opened in 1870 and holds over 500,000 works. Two hours is enough. The Impressionist galleries on the second floor are less crowded than the ground-floor Egyptian rooms, and the light in the American Wing is best before noon. Walk 10 minutes south to the Isabella Stewart Gardner Museum. Gardner built a Venetian palazzo in the Fenway in 1903 and filled it with Titians and Rembrandts around a courtyard that smells like wet stone and jasmine year-round. Admission is $20. Anyone named Isabella still gets in free. Lunch at El Pelon Taqueria on Peterborough Street, a 5-minute walk. A carnitas burrito runs $11 and the salsa verde has real bite. Walk Newbury Street from Massachusetts Avenue toward the Public Garden in the afternoon. The blocks get more expensive as you head east. The first two blocks have the better coffee shops and fewer tourists.

Day 3 crosses the Charles River. Take the Red Line from Park Street to Harvard Square, a 12-minute ride. Harvard Yard is free to walk and the elm trees give real shade in this heat. The Peabody Museum of Archaeology and Ethnology, founded in 1866, charges $15 and holds one of the strongest Native American collections on the East Coast. Lunch at Mr. Bartley's Burger Cottage at 1246 Massachusetts Avenue, open since 1960. A burger with sweet potato fries runs about $18. Afternoon, Red Line back to South Station and a 10-minute walk into the Seaport. The Institute of Contemporary Art sits right on the harbor with floor-to-ceiling glass and free admission on Thursday evenings. Fan Pier has outdoor benches where the salt air is strong and the planes from Logan pass directly overhead every 90 seconds. Dinner at Row 34 on Congress Street. Order the oysters at $3.50 each and a lobster roll for $28.

Boston is a walking city by American standards. The Freedom Trail alone covers 4 kilometres. The T subway system opened in 1897, the first in the country, and the age shows. Trains run every 5 to 8 minutes during the day and stop at 12:30 AM. A CharlieCard ride costs $2.40. Buy the card at any station kiosk rather than using the paper CharlieTicket, which charges $2.90 for the same trip. June temperatures currently sit around 30°C with 62% humidity, so carry water and expect to sweat. The North End and Seaport have almost no tree cover. Cambridge tends to be 2 to 3 degrees cooler because of the river and the elms around Harvard. About 27 kilometres of walking across the three days, with T rides filling the gaps between neighborhoods.