A celebration of Boston's 387th birthday, kids yoga in the park, a dazzling parade of costumes at the Cambridge Carnival, and lots more!

Friday, September 7

Boston Charter Day. Old South Meeting House, 310 Washington St., Boston. 9:30 a.m.-5 p.m. Come celebrate Boston's 387th birthday. Free. osmh.org.

Learning Spanish Circle Time. Leominster Public Library, 30 West St., Leominster. 10-10:30 a.m. New words, phrases, and songs in Spanish to build a Spanish vocabulary. For ages 3 to 5. Register ahead. Free. leominsterlibrary.org.

In the Yard: Boston in the War of 1812. USS Constitution Museum, Charlestown Navy Yard, Pier 1, Boston. 6:30-8 p.m. Discover the role of the Charlestown Navy Yard and its support of the USS Constitution and the Navy during the War of 1812. Free, donation suggested. ussconstitutionmuseum.org.

Saturday, September 8

Rube Goldberg Workshop. Newton Free Library, 330 Homer St., Newton. 10 a.m.-12 p.m. Design, build, test, and play with chain reactions, domino constructions, popsicle-stick snakes, and other experiments. For grades K to 5. Free. newtonfreelibrary.net.

Harvest Festival & Plant Sale. City Natives, 30 Edgewater Dr., Mattapan. 10 a.m.-2 p.m. Find harvest-season fun for the whole family, along with a great selection of cold-hardy seedlings and native plants well suited for fall planting. Free. thetrustees.org.

Kien's 17th Birthday Celebration. Stone Zoo, 149 Pond St., Stoneham. 10 a.m.-6 p.m. Celebrate white-cheeked gibbon Kien's 17th birthday through a slice of cake, and watching Kien enjoy special gibbon treats with friends. Free with admission. Members free; nonmember adults $17.95, children ages 2 to 12 $11.95, ages under 2 free. zoonewengland.org.

Beyond the Spectrum: Magnificent Musical Instruments. Museum of Fine Arts: Boston, 465 Huntington Ave., Boston. 10:30 a.m.-12:30 p.m. Take part during this adventure in art for children on the autism spectrum, explore the art and craft of making musical instruments, before making your own. Recommended for ages 8 to 12. $9. mfa.org.

Sensory Friendly Screening: Finding Nemo. Berkshire Museum, 39 South St., Pittsfield. 11 a.m. Come spend time at the Little Cinema as we watch this Pixar classic designed for families and children with sensory needs and those who have difficulty in a traditional movie setting. Recommended for ages 3 to 6. Members $3, nonmembers $5, ages under 4 free. berkshiremuseum.org.

Second Saturday Storytelling. Institute of Contemporary Art: Boston Watershed, 25 Harbor Shore Dr., Boston. 11-11:30 a.m. & 1:30-2 p.m. Connect with family and friends at the ICA Watershed through the art of storytelling, music, poetry, and movement. Recommended for ages 3 to 8. Free. icaboston.org.

The Boston Arts Festival. Christopher Columbus Waterfront Park, Boston. 11 a.m.-6:30 p.m. Join 50,000 visitors where you can meet a variety of arts and high-end craftspeople, including painting, photography, ceramics, jewelry, sculpture, and more. Through Sunday. Free. thebostonartsfestival.com.

Hands-On-History. Concord Museum, 200 Lexington Rd., Concord. 1-3 p.m. Drop by the Wright Tavern to get hands-on with history, with activities from writing with quill and ink, sewing a scented sachet, making soap, or tinsmithing. Free. concordmuseum.org.

Special Storytime: Heidi E.Y. Stemple and Jane Yolen. The Eric Carle Museum of Picture Book Art, 125 West Bay Rd., Amherst. 2 p.m. Come along with Principal Frank N. Stein into a bright, energetic classroom of Monster Academy with authors Stemple and Yolen. Free with admission. Adults $9, youths $6, ages under 1 free. carlemuseum.org.

A Wrinkle in Time. Worcester Public Library: Main Branch, 3 Salem Sq., Worcester. 2:30 p.m. Settle in and enjoy this colorful adaptation of the Madeleine L'Engle book following Meg and Charles as they travel across dimensions with the help of their friend and three mysterious travelers. Recommended for children under 12. Free. mywpl.org.

Sunday, September 9

Grandparents Day at LegoLand. LegoLand Discovery Center Boston, 589 Assembly Row, Somerville. 10 a.m.-7 p.m. Grandparents, accompanied by a child age 3-15, receive free admission on of National Grandparents Day! Brave grandparents who would like to try the new The Great LEGO® Race VR Experience with their grandchild will receive a free ticket with a paid child's ride. legolanddiscoverycenter.com.

Yoga in the Park for Kids. deCordova Sculpture Park & Museum, 51 Sandy Pond Rd., Lincoln. 10:30-11 a.m. Get moving as a family during this kid-friendly teacher-guided morning in the Sculpture Park. For ages 3 to 12. Adults, children $5. deCordova.org.

38th Victorian Fair. Main Street between Upham/Essex and Grove, Downtown Melrose. 11 a.m.-4 p.m. Look through nearly 200 booths filled with food, games, and fun, during this day featuring rides, local entertainment, and family fun. Free. melrosechamber.org.

Cambridge Carnival. Main Street and Ames Street, Cambridge. 12-6 p.m. Celebrate 26 years of delight, culture, and revelry during this dazzling parade of costumes and festival featuring international foods, multicultural craft vendors, and more fun. Free. cambridgecarnival.org.

Special Storytime: Deborah Blumenthal and Masha D'yans. The Eric Carle Museum of Picture Book Art, 125 West Bay Rd., Amherst. 2 p.m. Join author Deborah Blumenthal and artist Masha D'yans as they read from their new picture book Polka Dot Parade. Free with admission. Adults $9, youths $6, ages under 1 free. carlemuseum.org.