WASHINGTON, D.C. - You climb out of the Smithsonian Metro Station onto the National Mall, and right away your children's mouths are agape.

Before them is the towering and iconic Washington Monument. Beyond it, that image from the back of the penny, the Lincoln Memorial. And then, before you can set foot in the first museum, the sweat is beading on your forehead. Your older child is whining for an overpriced bottle of Dasani water. The little one needs a clean diaper.

Was this trip such a good idea after all?

It never got quite that bad during our recent trip to the nation's capital with Hadley, our rising second-grader and her 10-month-old sister, Harper.

We'd done the Mall before many times, but it's a new thrill with kids. How cool is it to see the hat Abraham Lincoln wore the night he died? Or to learn the security code name of the Declaration of Independence? (Stay tuned for a hint.)

And all for free.

Heck, kids get a jolt out of stuff that's not even on the tour, like hearing seven languages on the subway and riding an escalator for what seems like four stories to get out of the Woodley Park-Zoo Metro station.

For all the fun, we did figure out some things to make life easier with youngsters in the withering heat of summer.

Getting there

Park and ride: Find a hotel within walking distance from a Metro station, even better if the hotel doesn't charge for parking, as ours in Arlington didn't on weekends. We had a three-block walk to Ballston Station, where we could grab coffee and a muffin at either Cosi or Starbucks before getting on the subway.

The Metro: Washington's subway system is easy to understand and ride. By the second day, Hadley was carrying and punching her own ticket. All-day passes are $6.50, but it may not be worth it. Over three days, we spent less than $30.

Strollers: Think lightweight and compact. We took our jogger thinking it would roll better over the pea gravel along the Mall. But it was a huge hassle on the Metro and in the crowded museums, especially the Museum of Natural History, which has narrow doorways and teeny elevators.

Pack light for the Mall: You'll be in the seat of power of the most influential country on earth post-9/11. Prepare for metal detectors and bag searches whenever you enter a museum.

Sustenance

Bring your own bottle: Of water, that is. We laid out $2.50 for a 20-ounce bottle that's a buck at Kroger. We were more refreshed by the Italian ice we bought from a vendor for the same price. Noshing: The museum cafes can be more of a treat than you might think, but it's not fast-food cheap. The Museum of American History's cafe has eggplant in a spinach wrap and artichoke heart and red and yellow pepper antipasto, plus pizza, burgers and hot dogs for the kids. The bill for three of us was $28. For an old reliable, try the McDonald's in the Air and Space Museum, but don't expect to save much. Thanks to a limited menu, our bill there was $25.

Cooling off

Beat the heat: It's hard to get the kids rolling sometimes, but an early start is a good thing. It's less important if museums are on the itinerary, but if it's the National Zoo, well, these animals don't live in the same air-conditioned comfort as their fossilized ancestors in the Natural History museum. Fortunately, the zoo has refreshing misting stations along its walkways.

Cool your heels: Unless you're the member of your party who fits in the stroller, you'll probably relish a chance to give your feet a rest. Treat them to a dip in some cool water at the fountain behind the American History museum, the one next to the National Gallery of Art or at the new World War II Memorial.

Hot attractions

Tired of looking at dead things? When your children grow bored with dinosaur bones at the Natural History museum, head to the second floor to the Orkin Insect Zoo. There, they can hold a patent leather beetle, a silkworm or even a disturbingly large hissing cockroach. We also found a great spot there to give our own little crawly thing a break from the stroller. We turned Harper loose in the model termite mound for a few minutes.

And watch out for the monkeys: The National Zoo feels like a big park that happens to be occupied by pygmy hippos and capybaras and giant pandas. There's even poison ivy, conveniently labeled as an exhibit. But watch out for the uncaged monkeys that live in the trees in the middle of the zoo and might snatch your snacks. (Metro tip: Take the elevator out of the Woodley Park-Zoo station, which lands you one block closer to the zoo. Also, travel guides say the Cleveland Park station leaves an easier walk to the zoo.)

The only line in town: Credit the film "National Treasure," but our 6-year-old, Hadley, was willing to wait in line in the heat for 45 minutes to see the Declaration of Independence at the National Archives. The wait would have been longer, but the staff let us in to cool off in a movie theater while watching a documentary about the new preservation and security measures that protect the Declaration, the Constitution and the Bill of Rights. Then it's on to the dark, chilly rotunda to see the "charters of freedom" themselves.

The Declaration's code name? Well, let's just say it was given the name of a certain celebrity during a security upgrade of the archives building when it, ahem, left the building.