What are the best day trips from Boston?

Salem over Plymouth for a single day. The MBTA commuter rail leaves North Station every 30 minutes, runs 25 km north in about 30 minutes, and costs $7.50 one-way. The Peabody Essex Museum, which traces its collection back to 1799, is a 10-minute walk from the station and tends to hold your attention for 2-3 hours. Skip the witch-trial kitsch on Essex Street and head to the Merchant district instead, where Derby Wharf stretches 640 meters into the harbor. The wind off the water drops the temperature 5-8 degrees on summer afternoons. For dinner before the train back, Ledger Restaurant on Washington Street serves oysters in a converted 1818 bank building, with heavy stone walls keeping the dining room cool even in August. The vaulted ceiling and candlelight do more for a couple's evening than any dinner cruise in Boston Harbor. You'll be back at North Station by 9:30 pm.

Newport sits 115 km south, about 90 minutes by car with no direct train. The Cliff Walk runs 5.6 km along the Atlantic shoreline past the Breakers and Marble House, and you'll feel the salt spray on your face the entire route. Mind you, the path turns rocky and uneven south of Rough Point, so wear proper shoes, not sandals. One mansion tour is enough. The Breakers (built 1895, $29 per person) is the obvious pick, but Marble House is smaller, less crowded on weekdays, and the Gold Ballroom still smells faintly of old wood and polish. For lunch, Clarke Cooke House on Bannister's Wharf has had the same harbor-facing patio tables since the 1970s, and a lobster roll runs about $38. The drive back along Route 114 through Tiverton passes farm stands selling peach cider through September. Worth noting, Newport works better on a weekday. Summer Saturdays pack the Cliff Walk so tightly you'll spend more time waiting than walking.

Providence is the day trip that works when one of you wants art and the other wants food. The MBTA commuter rail from Back Bay runs 80 km south in about 75 minutes for $12.25 one-way. The RISD Museum at 224 Benefit Street ($20, closed Mondays) holds more than 100,000 objects in a building where you can smell old oak floors in the textile galleries. While one partner lingers with the Monet and the 12th-century Buddha, the other can walk 15 minutes to Federal Hill on Atwells Avenue, where the pine-nut smell from Italian bakeries hits you a block before you see them. Venda Ravioli at 275 Atwells has been open since 1981 and still sells fresh pasta by the pound from a case fogged with steam. Meet back at WaterPlace Park by 5 pm. If you time it for a WaterFire night, roughly 25 Saturday evenings from May through November, the smell of cedar and pine from the floating bonfires carries across the whole park.

The Provincetown fast ferry leaves Long Wharf around 8:30 am from late May through mid-October, covers 80 km across Cape Cod Bay in 90 minutes, and costs about $65 one-way. Provincetown is 5 blocks wide. You can walk the entire Commercial Street in 40 minutes, and the galleries between Kiley Court and Pearl Street are better than most of what hangs in Boston's Newbury Street shops. The Portuguese Bakery at 299 Commercial Street has been selling malasadas, warm sugar-dusted fried dough, since the 1960s. You'll hear the crunch of sand underfoot on every sidewalk. Race Point Beach, a 10-minute taxi from the pier, faces open Atlantic and the water stays cold, around 15°C even in July. That said, the last ferry back leaves around 6:30 pm in early season and 8 pm in peak summer, so check the schedule before you commit to a beach sunset. The return crossing can get choppy. Sit mid-deck if either of you gets seasick.

Concord works when one of you cares about the Revolution and the other would rather swim. The MBTA commuter rail from North Station runs 30 km west in about 40 minutes for $7.50 one-way. The Old North Bridge, where the first shots of April 19, 1775 were fired, is a 25-minute walk from the station through quiet residential streets lined with maples. The Concord Museum at 200 Lexington Road ($15 admission) holds one of Paul Revere's signal lanterns. Walden Pond is 3 km south of the town center, the $30 parking fee keeps crowds manageable on weekdays, and the water in the kettle pond reaches a swimmable 24°C by late June. The pebbly bottom feels smooth underfoot. Split the morning. The history half at the bridge, the nature half at the pond. Then meet for lunch at Main Streets Market and Cafe on Main Street, where a sandwich and iced coffee run about $18. Back in Boston by 4 pm, plenty of time for dinner.