A huge new home for the Madison Children's Museum gives kids plenty of creative places to burn energy (608/256-6445; madisonchildrensmuseum.org). On the first floor of the $5 million building just off Capitol Square, the 5-and-under set will be captivated by the Ewok villagelike Wildernest area, with its tree-trunk huts and dinosaur-bone bridge. Older youngsters will likely race up to the second floor to run in a giant gerbil wheel or construct contraptions in the Possible-opolis area.
Elsewhere in Madison, take the kids for a generous scoop of campus-made ice cream at Babcock Hall Dairy Store, the flagship of the University of Wisconsin's respected dairy program (608/262-3045; babcockhalldairystore.wisc.edu). Older kids will enjoy free tours of the Wisconsin State Capitol (608/266-0382; wisconsin.gov) or the summer butterfly show at Olbrich Botanical Gardens (608/246-4550; olbrich.org).
Surrounded by some of northern Wisconsin's 4,200 lakes, Minocqua qualifies as the quintessential resort-area town. Popcorn- and fudge-scented air hums with the buzz of speedboats and the putt of pontoons. Families return year after year to enjoy lake sports as well as local attractions and events.
Kids can feed the animals at Wildwood Wildlife Park (715/356-5588; wildwoodwildlifepark.com); cheer on competitors at Scheer's Lumberjack Show (715/356-4050; scheerslumberjackshow.com); or spend the afternoon at nearby Eagle River's Northwoods Children's Museum, with an ambulance, dress-up attic, mock campground and fire tower (715/479-4623; northwoodschildrensmuseum.com).
A premier family attraction here is the National Railroad Museum (920/437-7623; nationalrrmuseum.org). One of the nation's largest rail museums, it houses everything from decorative train drumheads to a massive Big Boy steam locomotive -- and yes, you can take a train ride.
Start your visit with the 25-minute movie on steam locomotives. Then explore indoor and outdoor exhibits that include a futuristic Aerotrain from the 1950s.
Sports fans will enjoy a trip to Lambeau Field, which offers behind-the-scenes tours all year long, plus photo ops with a bronze statue of legendary coach Vince Lombardi (920/569-7500; lambeaufield.com). If you just want a place for the kids to stretch their legs, head to Green Bay Botanical Garden, where 47 acres of quiet beauty are worth exploring year-round (877/355-4224; www.gbbg.org).
What almost certainly ranks as one of the most kid-friendly vacation spots in the Heartland revolves around giant indoor and outdoor water parks. Beyond the parks, be sure to see the Dells, the unique, craggy bluffs rising over the Wisconsin River like stacks of sandstone pancakes. Some of the best views are from double-decker excursion boats (608/254-8555; dellsboats.com). And attractions in nearby Baraboo, including Circus World Museum (608/356-8341; circusworld.wisconsinhistory.org) and the International Crane Foundation (608/356-9462; savingcranes.org), make it worth leaving the pool.
Mississippi River cruises are among the attractions in this University of Wisconsin town (877/647-7397; mississippiexplorer.com). When on land, take the family to Rudy's Drive-In (608/782-2200; rudysdrivein.com). During classic-car nights, roller-skating carhops don poodle skirts and serve 40 drive-up stations and indoor booths. Rudy's menu offers typical fast food as well as specialty options such as a vegetarian walnut burger.
Racine's North Beach is one of Midwest Living® editors' top picks for Midwest city beaches. Amazingly clean, the 1.2 miles of sandy Lake Michigan coast welcome the Extreme Volleyball Professional tour each summer. A wetland, Kid's Cove playground and a zoo border the 50-acre expanse; to the south, boats bob in Racine Yacht Club's marina. To rent a kayak or personal watercraft, head to Pier 29 Water Sport Rentals at the southern end of Michigan Boulevard (262/634-2929; pier29watersports.com). For just $15 an hour, you can paddle around the harbor and drink in the views of this perfectly groomed destination.
Hayward and its neighbors offer a cluster of peaceful retreats for family outdoor activities. With 267 lakes in Sawyer County and 2,000 miles of streams, fishing is king here. But the Namekagon River also offers stunning canoeing, kayaking, cruises and tubing (715/635-8346; nps.gov/sacn).
Kids can ogle the giant 40-foot muskie at the Fresh Water Fishing Hall of Fame and Museum (715/634-4440; freshwater-fishing.org) or explore the Curiosity Center at Cable Natural History Museum (715/798-3890; cablemuseum.org). As in Minocqua, 100 miles to the east, Scheer's Lumberjack Show entertains visitors of all ages (715/634-6923; scheerlumberjackshow.com).
One of Milwaukee's top draws for families is Discovery World (414/765-0066; discoveryworld.org). In an airy white building that juts out over Lake Michigan, this museum provides hands-on ways to learn about science and the environment. Les Paul's House of Sound, a recent addition to the museum, explores the history of the electric guitar and lets visitors craft their own songs (pictured).
Older kids will get a kick out of the Harley-Davidson Museum (877/436-8738; h-dmuseum.com), where a movie room lets you board one of 10 Harleys and "ride" along Midwest farms and rivers. Another fun family activity: Any of the city's many festivals, including Polish Fest, Bastille Days, Greek Fest, Festa Italiana, German Fest, African World Festival, Arab World Fest and Irish Fest. Check the events calendar on the city's website for details (visitmilwaukee.org).
Visit Milwaukee 
Five state parks and more than 250 miles of shoreline in Door County offer family outdoor activities such as biking, hiking, swimming, kayaking and sunbathing (plus exploring the area's lighthouses).
Kids can also steer a steamship at the Door County Maritime Museum (920/743-5958; dcmm.org); create a mosaic at Hands On Art Studio (888/868-9311; handsonartstudio.com); or catch a ferry with mom and dad to explore nearby Washington Island with its beaches, museums and farms (920/747-2179; washingtonislandchamber.com). Stop for a thick malt or fresh-brewed root beer at Wilson's Restaurant and Ice Cream Parlor, an Ephraim institution since 1906 (920/854-2041; wilsonsicecream.com).
Door County 
This picturesque park (20 miles southeast of Duluth) encompasses waterfalls that tumble into swimming holes and a covered bridge that spans the falls. Short scenic trails are perfect for families with small children, and parents can listen to the peaceful sound of water falling over stones while the kids splash around.
The lush farm country south and west of Madison has a sprinkling of surprisingly hip small towns, such as Mineral Point, a historic mining town that has reinvented itself as a center for the arts. Shake Rag Alley Center for the Arts in Mineral Point offers hands-on classes both for kids and adults (608/987-3292; shakeragalley.com).
Other family-friendly attractions in the area include Cave of the Mounds National Natural Landmark (pictured), where an hour-long tour provides fascinating, up-close looks at delicate crystal formations (608/437-3038; caveofthemounds.com), and Sugar River State Trail, a 24-mile recreation trail for bicycling and walking (608/527-2334; www.dnr.state.wi.us).
Green County Tourism 
Perched on a peninsula on Wisconsin's northern tip, tiny Bayfield (population: 611) prepares each spring for the thousands of travelers heading that way as soon as summer break starts. In and around the town, bicycling is popular with families; rent bikes for $6 an hour or $25 for the day at Bayfield Bike Route, and hop on the Brownstone Trail for an easy ride along Lake Superior (715/209-6864; bayfieldbikeroute.com).
Then there's the lure of the nearby Apostle Islands National Lakeshore, a 22-mile archipelago in Lake Superior known for its rocky hiking trails, lighthouses, stunning views and sea caves (715/779-3397; nps.gov/apis). Ferries, sailboats and kayaks make the Apostles a destination for adventurers of all skill levels.