What are the best day trips from Washington DC?

Mount Vernon works for couples because one of you wants George Washington's estate and the other wants the 4-acre garden. Admission runs $28 per adult. The distillery and gristmill sit 4.8 km south of the main house, reachable by free shuttle, and the rye whiskey tasting is $5 on top. The drive from Washington DC takes about 30 minutes south on the George Washington Memorial Parkway, which follows the Potomac and might be the best scenic drive in the mid-Atlantic. The Potomac Riverboat Company ferry departs Alexandria's waterfront around 10:30am and docks before noon, returning mid-afternoon. That schedule gives you about 4 hours on the grounds, tight for the full mansion tour (45-minute guided walk, timed entry) plus the garden and outbuildings. If you drive, you control the clock. Stop in Old Town Alexandria on the way back for dinner. The waterfront blocks along King Street run $30-80 per person, and the quieter tables tend to be a block inland where the foot traffic thins out.

Annapolis is 50 km east of Washington DC, roughly an hour by car with no practical public transit. City Dock is the reason to go as a couple. The Maryland State House (1772, the oldest state capitol still in continuous legislative use) sits at the top of the hill, and the waterfront fans out below. One of you walks the Naval Academy grounds (free, photo ID required at Gate 1 on Maryland Avenue) while the other browses the shops. Meet for lunch at Cantler's Riverside Inn on Forest Beach Road, where medium male crabs currently run about $70 per dozen. Cantler's sits on Mill Creek, not downtown, so you need the car. Worth the 10-minute drive for the brown paper, the wooden mallets, the smell of Old Bay rising off the steam table. If you prefer staying waterfront, Carroll's Creek Cafe on Compromise Street has a deck over Spa Creek and crab cakes around $38. Sailing charters leave from the Annapolis Sailing School dock, typically $65 per person for a 2-hour sunset sail that gets you back by dusk.

Shenandoah National Park is the pick when one of you wants to hike and the other wants to sit at an overlook reading. Skyline Drive runs 169 km along the Blue Ridge crest, entrance $30 per vehicle. The nearest access from Washington DC is Front Royal, 120 km west, about 90 minutes on I-66. Drive to milepost 51 together. The hiking partner takes the 2.4-km round trip down to Dark Hollow Falls (about 45 minutes, where the water drops 21 meters and you can feel the spray on your skin at the base). The resting partner stays at Big Meadows with a coffee and the southward view toward Stony Man peak. Meet at Big Meadows Lodge for a late lunch. Try the blackberry pie. In August, the ridge runs 5-8 degrees Celsius cooler than Washington DC's valley floor, a real break from the humidity. The wildflower meadows are at peak color through mid-September. Back in Washington DC by 7pm if you turn around near the midpoint.

Baltimore over Gettysburg if only one of you cares about the Civil War. MARC Penn Line trains leave Washington DC's Union Station roughly every hour, arriving at Penn Station Baltimore in under an hour. A 15-minute walk south from there reaches the Inner Harbor. The National Aquarium ($39.95 adult) fills 2-3 hours. The American Visionary Art Museum on Key Highway, about 1.2 km south along the waterfront, tends to be the more interesting stop for couples, with outsider-art installations in a converted warehouse. Admission is $16. For lunch, walk 10 minutes east to Fells Point, where Thames Street runs along the water. Thames Street Oyster House does a lobster roll at lunch that draws a line by 12:30. The bar seats work if you arrive by 11:45. You'll smell the charcoal and brine from the end of the block. Harpers Ferry (100 km northwest, reachable by MARC Brunswick Line from Washington DC on weekdays) is the other strong option but needs good weather and two willing walkers. The town sits at the confluence of the Potomac and Shenandoah Rivers, and the heights trail takes about 90 minutes.