Outdoor summer fun can be as inexpensive as putting the kids in bathing suits and turning on the sprinklers. But if you’re looking for something a little more adventurous, try exploring these free activities around the AMC region.

Massachusetts
In Massachusetts, the Highland Street Foundation has collaborated with cultural organizations around the state to offer 10 Free Fun Fridays during the summer. On each Friday, several museums and other family-friendly sites will offer free admission. Here are my picks for outdoor fun each week.

June 28: Freedom Trail Foundation Walk Into History Tour
Boston
Learn about the American Revolution as you walk the 2.5-mile route with a costumed guide.

July 5: Mass Audubon's Boston Nature Center
Mattapan
This urban sanctuary offers 2 miles of trails and boardwalks through meadows and wetlands, as well as an outdoor playspace for kids.

July 12: Larz Anderson Auto Museum
Brookline
Your kids may be attracted by the car collection, but take some time to also enjoy this museum’s grounds. The park features a pond, walking paths, and great picnic spots with skyline views of Boston.

July 19: Garden in the Woods
Framingham
Run by the New England Wild Flower Society, Garden in the Woods offers walking paths through a wonderful collection of native plants, including more than 100 rare and endangered species.

July 26: The Children's Museum in Easton
Easton
With a two-story tree house, butterfly garden, African garden, and dinosaur garden where kids can climb into the fossil pit, this museum offers lots of outdoor fun. Picnic tables also beckon, so bring lunch or a snack.

August 2: Arnold Arboretum
Boston
The Arboretum’s 281 acres are actually free and open to the public every day of the year, but expect more families to be exploring on this Friday. Check out the hidden letterboxes, free discovery packs, and other activities for families.

August 9: The Boston Harbor Islands
Boston
Free ferry travel will be offered to the two most popular Boston Harbor Islands, Georges Island (with historic Fort Warren, Plays in the Park, and ranger-guided tours) and Spectacle Island (with a lifeguard-supervised beach and 5 miles of trails). Tickets will be distributed on a first-come, first-served basis at Long Wharf-North, near the Aquarium subway station, beginning at 8:00 am. Check the website for details on ticket limits.

August 16: Springfield Museums
Springfield
These four museums grouped around a quadrangle include a science museum with a butterfly house, planetarium, and live animal center. Outdoors, visit the Dr. Seuss Sculpture Garden, created in honor of one of the city’s most famous sons.

August 23: Fruitlands Museum
Harvard
The grounds of this museum, set at the site of an experimental 19th-century utopian community, offer 3 miles of hiking trails through forest, wetlands, and meadows. An Art in Nature exhibit will be displaying the work of 10 sculptors until November 3.

August 30: EcoTarium
Worcester
This indoor-outdoor museum dedicated to science and nature offers wildlife, a digital planetarium, a narrow-gauge train, and more. The treetop canopy is set to close August 25, so visit earlier if you want to walk it.

Check the website for specifics on all Free Fun Friday events.

For other inspiration, read about five favorite outings with kids (especially tweens) recommended by Outdoors with Kids Boston author Kim Foley MacKinnon.

Elsewhere in the AMC Region
I don’t know of an equivalent to Free Fun Fridays in other parts of the Northeast, but families can still find plenty of free outdoor activities. Here are a few ideas.

New York City
The Bronx Zoo and the The New York Botanical Garden are free to the public every Wednesday. The Botanical Garden is also free on Saturday mornings, from 10 to 11 a.m. And there’s always Central Park. Also try these family-friendly outings recommended by Cheryl and William de Jong-Lambert, the authors of Outdoors with Kids New York City.

Philadelphia
In the Philadelphia area, try these five great hiking, biking, and paddling spots recommended by Susan Charkes, author of Outdoors with Kids Philadelphia. AMC’s new Kids Outdoors online community for Philadelphia offers more local trip suggestions, maps, and tips for getting the children in your life outdoors. Boston and New York communities are also available.

Washington, D.C.
Many residents and tourists know about the extensive free museums and other national attractions in Washington, D.C. A free activity that features the outdoors is walking or biking the C&O Canal Towpath, which follows the shore of the Potomac from Georgetown to Cumberland, Maryland. Best Day Hikes near Washington, D.C. author Beth Homicz shares ideas for summer outdoor fun and recommended family day hikes in and around Washington, DC.