Explore the wondrous world of fungi at a Fabulous Fungus Fair, go trick-or-treating and make seasonal crafts at a Monster Mash, or take a guided tour through historic Sleepy Hollow Cemetery.

 Friday, October 26

Backyard and Beyond: Forest Fridays. Discovery Museum, 177 Main St., Acton. 10-10:45 a.m. Come outside and do a nature-based activity based on the weather and season, either in the Discovery Woods our out on the conservation land adjacent to the Museum. Designed for ages 2 to 6. Free with admission. Members free; nonmembers $14.50, ages under 1 free. discoveryacton.org.

Toddler and Preschool Play. The Eric Carle Museum of Picture Book Art, 125 West Bay Rd., Amherst. 11-11:30 a.m. Experiment with materials selected especially for young explorers in the Art Studio. Free with admission. Adults $9, youths $6, ages under 1 free. carlemuseum.org.

Saturday, October 27

Autumn Discovery Day. South Shore Natural Science Center, 48 Jacobs Ln., Norwell. 10 a.m.-3 p.m. A day of hands-on exploration experiencing the fun of the season. Free with admission. Members free; nonmembers $5, ages under 2 free. southshorenaturalsciencecenter.org.

Play Date: Spooky Not Scary Contemporary Escapades. Institute of Contemporary Art: Boston, 25 Harbor Shore Dr., Boston. 10 a.m.-4 p.m. Kids rule the ICA during this time when we use everyday and repurposed materials to create serious, silly, or even spooky puppets, and enjoy activities throughout the museum. Members free; adults with children under 12 free, youth free. icaboston.org.

Monster Mash. Springfield Museums, 21 Edwards St., Springfield. 10 a.m.-5 p.m. Enjoy this day-long party featuring a rotating cast of activities and crafts, some trick or treating, to the appearance from the Grinch, crafts, and more. Free with admission. Members free; nonmember adults $25, youths 3 and up $13, ages under 3 free. springfieldmuseums.org.

Family Yoga Class. Newton Free Library, 330 Homer St., Newton. 10:30-11:30 a.m. Participate in and learn cooperative games, age-appropriate poses, partner poses, breathing exercises, and mindfulness activities. Designed for ages 3 to 12. Free. newtonfreelibrary.net.

Fabulous Fungus Fair. Harvard Museum of Natural History, 26 Oxford St., Cambridge. 2-4 p.m. Explore the wondrous world of fungi, as you look at the mushrooms, yeasts, and molds found in gardens, forests, labs, and yes, refrigerators. Free with admission. Members free; nonmember adults $12, youth 3 and up $8, ages under 3 free. hmnh.harvard.edu.

Haunted House Spooktacular. Federated Church of Ayer, 21 Washington St., Ayer. 4-9 p.m. A family-friendly Halloween Haunted House. The first couple of hours will offer not-so-spooky fun for the little ones, then, from 6-9 p.m., get ready to be spooked!  $3 for ages 10 and under; $5 for ages 11 and up. www.jacneed.com/ASYD/AyerShirleyDrama.htm.

Decades Rewind. The Hanover Theatre, 2 Southbridge St., Worcester. 7:30 p.m. Be transported back to the 60s, 70s, and 80s during this live concert and theatrical performance all wrapped into one magical night. $25-52, ages 15 and under free with adult purchase. thehanovertheatre.org.

Sunday, October 28

Boston Artists Ensemble. Newton Free Library, 330 Homer St., Newton. 2-3 p.m. Join former BSO cellist Jonathan Miller and members of the Boston Artists Ensemble for an afternoon concert. Free. newtonfreelibrary.net.

Sleepy Hollow-een Tour. Concord Museum, 200 Lexington Rd., Concord. 3:30-5 p.m. Take a tour through historic Sleepy Hollow Cemetery with a Concord guide and learn stories across the generations. Register ahead. Members $5, nonmembers $10. concordmuseum.org.