Myrtle Beach or Washington DC?

There is no contest here. Myrtle Beach sits on the Grand Strand, with pale sand, small waves and a summer sea warm enough to swim in for hours. If the central blocks are too crowded, the calmer dune-backed beaches at Surfside and Garden City are close by.

Washington's rivers are not for swimming, and the nearest sand is on the brackish Chesapeake around Annapolis. Reaching proper Atlantic surf means a weekend on the Delaware or Maryland shore, so in practice a hotel pool is how you cool off.

Washington eats far better, and its strength is range. You can have Ethiopian cooking around Shaw and U Street, pupusas in Columbia Heights, an afternoon of grazing at Eastern Market and Union Market, and ambitious tasting menus around Logan Circle and the waterfront.

Myrtle Beach feeds crowds with buffets, pancake houses and chains. Its best meals are a drive away, at the seafood restaurants of Murrells Inlet or the Calabash-style fry houses over the state line. Both places serve good local seafood, but only Washington makes a week of eating out worthwhile.

This category alone can decide the trip. Washington lines the National Mall with free museums, from Natural History and Air and Space to the National Museum of African American History and Culture and the National Gallery. Around them stand the Capitol, the Lincoln Memorial and, across the river, Arlington Cemetery, and even a week is barely enough.

Myrtle Beach is a twentieth-century resort. Its main sights are Brookgreen Gardens, with sculpture among the live oaks and the history of the plantation, and the Moorish-style Atalaya next door. Most visitors have seen both in a day.

Washington has the better nights out, thanks to its young crowd of staffers and students. There are cocktail bars and rooftops along 14th Street and U Street, a rowdier late strip in Adams Morgan and dive bars on H Street, all at their busiest from Thursday to Saturday.

Myrtle Beach goes out resort-style, with beach bars, themed bars and dance clubs around the boardwalk in summer, and the Carolina shag still danced in North Myrtle Beach. It is louder and more seasonal, and outside summer it goes quiet early.

Washington offers more outdoors and more varied ground. Rock Creek Park and the C&O Canal towpath run straight out of the city. Half an hour upriver, the Potomac pours through a rocky gorge at Great Falls, and the ridge hikes of Shenandoah are within a morning's drive.

Myrtle Beach is flat coastal country, better for water and wildlife than for walking. Highlights include herons and alligators at Huntington Beach State Park, kayaking among the cypress of the Waccamaw swamps, dolphin cruises and dozens of golf courses.

Washington is better placed for day trips. Alexandria is a short Metro ride away, Baltimore is under an hour by train and Philadelphia is about two hours by fast train. Mount Vernon, Annapolis and the Civil War battlefields at Gettysburg and Antietam are all within a drive.

From Myrtle Beach the outstanding outing is Charleston, a long day two hours to the south. Shorter trips go to Georgetown's old port, Pawleys Island and Wilmington. Every one of them needs a car.

Both cities work well with children, but Myrtle Beach is built around them in a way Washington is not. Gentle surf, resort hotels with lazy rivers, the aquarium, water parks and endless pirate-themed mini-golf make the days easy, though the summer heat and constant driving wear parents down.

Washington's strength is that its best sights are free and made to teach: dinosaurs at Natural History, rockets at Air and Space, and the National Zoo. On the other hand, the long, exposed Mall tires small legs in summer, and there are no theme parks or beaches nearby.

Washington is far easier without a car. The Metro reaches the Mall, Arlington, Alexandria and the airport, and every station has lifts. Bike-share docks are everywhere and the flat grid is pleasant to walk. The main gap is that Georgetown has no station.

Myrtle Beach is spread along the length of the Grand Strand, with few pavements and sparse buses, so a car is close to essential. Walking only works within a resort area or along the beach itself, and summer traffic on Kings Highway can be slow.

Neither city is a shopping destination, but Washington has more character. On M Street and Wisconsin Avenue in Georgetown, boutiques and antique shops sit in old brick buildings, and CityCenterDC gathers the luxury labels. Eastern Market and Union Market add crafts and small makers.

Myrtle Beach means outlet centres, huge beachwear stores and The Market Common. It is useful for bargains but has few independent shops. Its one real local craft is the sweetgrass baskets sold along the coast road to the south.

Myrtle Beach is the cheaper place to stay. Its vast supply of motels, hotels and rental condos keeps rooms affordable, particularly outside July, and kitchens cut the cost of meals. A car and paid attractions do add up, though.

Washington's hotels and restaurants are expensive all year, and more so in cherry blossom season. Its saving grace is that the museums, the zoo and the memorials are free, and staying in Arlington can bring the cost of a room down.

Washington is a real theatre city, with Arena Stage, the Shakespeare Theatre Company, Woolly Mammoth, Ford's Theatre and touring musicals at the National Theatre. It also has the National Symphony and the Washington National Opera, live music around U Street and summer concerts on the lawn at Wolf Trap.

In Myrtle Beach a night at the theatre means the big variety houses, with country, gospel and Christmas revues, dinner shows with knights or pirates, and touring country and rock acts. These are polished family shows, but there is no serious drama or classical music.

Neither place is built for rest, and both rely on hotel spas because neither has a bathing tradition. What differs is where you find calm. In Myrtle Beach it is the quieter shore around Pawleys Island and the spring and autumn shoulder seasons. In Washington it is an early walk around the Tidal Basin or an hour in the Dumbarton Oaks gardens or the National Arboretum.