The Grand Canyon; Arizona
Absolutely nothing will prepare your family for the first time you see this 227-mile-long, 5,000-foot-deep wonder of the world. The brand-new Skywalk makes you feel as if you're floating over the canyon as you stroll along the glass-bottomed path 70 feet from the ridge. For a more relaxing, scenic tour of the area, climb aboard the Grand Canyon Railway, a steam-engine train that travels from Williams, Arizona, to the South Rim of the canyon.
Niagara Falls; New York and Canada
Hear, smell, feel the spray of the 6 million cubic feet of water that rushes over this New York/Canadian gorge every minute.
Glacier Bay National Park and Preserve; Alaska
Quick -- before global warming melts them away, take a look at these giant, spectacular remnants of the Ice Age.
Statue of Liberty; New York City
Lady Liberty is probably the most recognizable symbol of American freedom. So it's a safe bet that kids of all ages will get a kick out of seeing her -- even if it's just a quick look from the deck of the Staten Island Ferry (the city's best freebie). To get up close and personal, take the Circle Line to Liberty Island, where you can climb the stairs to her 10th-floor observatory. Bonus: The boat also stops at the Ellis Island Immigration Museum.
Liberty Bell; Philadelphia
Let your kids check out the famous crack, then head inside the museum for some interactive exhibits, like one on 18th-century bookbinding.
Lincoln Memorial; Washington, D.C.
Walk up the 98 steps (or run up them, Rocky-style) to let your children stand at the feet of good ol' Honest Abe.
There's nothing like standing on an actual battlefield to get a real sense of history. Sign your child up for the fun, hands-on Junior Rangers program to learn more about this site, where the war's bloodiest battle took place and Abraham Lincoln gave the Gettysburg Address, one of his most famous speeches.
The landmark courthouse is the historic site where General Lee surrendered to General Grant, marking the end of the Civil War.
The armies fought here to gain control of the mighty Mississippi River. At the National Military Park, you can see the weapons they used, as well as the U.S.S. Cairo gunboat.
New York City
Times Square, Central Park, Broadway -- what's not to love about the Big Apple?
There's more to Beantown than just the Red Sox. Remember a little uprising called the Boston Tea Party? Visit all the sites on the three-mile Freedom Trail.
Cannon Beach; Oregon
It's hard to find a beach that's not cluttered with giant hotel resorts, wild volleyball games, or jet skis zipping through the water. But this West Coast gem is one of the few spots that still feels and looks untouched. Explore the tidal pools for colorful sea creatures, and take part in one of the family-friendly festivals held throughout the year, such as the Puffin Kite Festival and the super-popular Sand Castle Building competition.
Poipu Beach; Hawaii
With a naturally formed wading pool and a shallow bay for swimming, this is one of the most kid-friendly beaches on Kauai, one of Hawaii's less touristy islands.
Ocracoke Lifeguard Beach; North Carolina
On the southernmost tip of the Outer Banks, this beach is so private that wild "banker ponies" still roam free.
Red Rock Canyon National Conservation Area; Nevada
Who would think that taking just a short drive west of the busy Vegas strip would land your family in the middle of a beautiful, serene desert? Pack a picnic and watch the sun set behind the sand. Just wait for your kids to ooh and aah as the sky turns a brilliant shade of red and the light bounces off the rocks, making the sky look like it's on fire.
Painted Desert; Arizona
This vast desert is home to the Petrified Forest, which features fossilized hunks of ancient trees.
Death Valley; California
At 282 feet below sea level, this hot spot has the lowest elevation in the country -- and is a prime location for stargazing.
Mount Rushmore; South Dakota
Let's face it: This larger-than-life sculpture of the giant faces of four dead presidents is a bit odd. But it's probably just strange enough to fascinate your children. Mount Rushmore is a tribute to the power, skill, and dedication of the nearly 400 men who worked 14 years to complete the 60-foot carvings of George Washington, Thomas Jefferson, Theodore Roosevelt, and Abraham Lincoln, all chosen to represent the first 150 years of American history.
Hoover Dam; Arizona and Nevada
Straddling the border of these two western states, the 726-foot-tall dam is one of the world's great engineering feats.
Golden Gate Bridge; San Francisco
The bridge offers a fantastic view of the city, even through Frisco's trademark fog. Walk across the span and feel it vibrate underneath you as traffic rushes by.