Walk up the paved, stroller-friendly trail at the Mount Rushmore National Memorial, in Keystone, to see the presidential sculptures. Drop in at one of the ranger-led 14-minute films about how and why the mountain was carved.
Stop by Shelby Farm Park, in Memphis, one of the largest urban parks in the U.S. Hop on the paved Chickasaw Trail that will take you past a range of buffalo. Don't miss the Woodland Discovery Playground, which has a giant treehouse and cool structures to climb.
Remember The Alamo! The restored area in downtown San Antonio has medical instruments and tools kids can touch, plus a film that explains the significance of the battle. If the kids get antsy, take them for a walk around the pond out back.
In Salt Lake City, the Utah Museum of Contemporary Art schedules monthly stroller tours of its contemporary exhibition for the 3-and-under crowd. For school-age kids, the museum hosts Family Art Saturdays on the second Saturday of each month.
The whole family can learn how maple syrup is made -- and taste all four different grades of the fave pancake topping at the Morse Farm Maple Sugarworks tour, in Montpelier. Don't forget to take your child's picture in a cardboard cutout to prove that he's a SAP (syrup-appreciating person).
Children can play with flight simulators, watch air traffic from an observation tower, and explore dozens of planes from all eras as well as the Space Shuttle Discovery in a pair of enormous hangarsat the Steven F. Udvar-Hazy Center, in Chantilly. It's a companion to the Smithsonian's National Air and Space Museum (also free) that's less than half an hour away in Washington, D.C.
A former World's Fair site, the Seattle Center is chock-full of attractions and museums, but kids will have a blast exploring the sculpture garden and the fountains.
Washington, D.C., is a mecca of free family activities. The Washington Monument recently reopened, and the 200th anniversary of the "Star-Spangled Banner" will bring a bunch of free special events this September. The National Gallery of Art is hosting an Edgar Degas and a Mary Cassatt exhibit through October, which is perfect for kids who love ballet, while animal aficionados will adore seeing the National Zoo's year-old panda. Stay over at the new Marriott Marquis Washington, DC, which is six blocks from the National Mall. Introductory rates start at $92 per night for Summer Weekend Deal stays of two nights or more; marriott.com.
In Bramwell, Pinnacle Rock State Park is known for its unusual rock outcroppings. It's an easy walk to a few of the scenic overlooks. And be sure to check out the playground, which has a mock Pinnacle Rock for children to climb.
There's a reason why the University of Wisconsin's Geology Museum, in Madison, attracts a lot of enthusiastic kindergarten and first-grade school groups -- it has neat exhibits galore, including rocks and minerals, meteorites, and dinosaur skeletons.
Shaped like turrets and towers, the cool rock formations of Castle Gardens Recreation Site (in the central part of the state, about 45 minutes east of Riverton) are worth a close-up look. Encourage your kids to examine the Native American carvings on the sandstone and figure out the story that's being told in the art.
Mark your calendar for these dates when the typical admission to attractions across the country is waived.
September 27 Museum Day Live! Sign up for two free tickets to one of more than 500 museums nationwide for this event sponsored by Smithsonian magazine; smithsonianmag.com/museumday
First Saturday & Sunday of the month Bank of America and Merrill Lynch credit-card holders receive one free admission to 150 attractions nationwide as part of the Museums on Us program; museums.bankofamerica.com
August 25, September 27, November 11 Receive free entrance at any of the nation's 103 national parks that usually charge; nps.gov
Select Dates Target sponsors free or reduced-price admission dates to attractions in your area; some children's museums participate in this program; corporate.target.com
Originally published in the July 2014 issue of Parents magazine.
This piece was accurate at publication time, but all prices, offerings and availabilities are subject to change. Please contact each hotel and attraction for up-to-date rates and information before taking your trip.