The Old Stone House presents a “Taste of History Cooking Session: Construction of a Bake Oven” at 10 a.m. Saturday. Tours of the historic site run from 10 a.m. to 5 p.m. Saturdays and from noon to 5 p.m. Sundays. The Old Stone House is at the intersection of Routes 8, 173 and 528 and is operated by Slippery Rock University. Call 724-738-2409.

Harmony Museum, 218 Mercer St., Harmony, offers guided tours 1 to 4 p.m. daily except when the museum is closed Mondays. Admission is $7 for adults, $6 for senior citizens, and $3 for youths ages 6 to 17. Call 724-452-7341 or visit www.harmonymuseum.org.

Meadowcroft Rockshelter and Historic Village, 401 Meadowcroft Road, Avella, Washington County, hosts an atlatl competition Saturday. The atlatl is an ancient hunting spear-thrower. Meadowcroft is open noon to 5 p.m. Wednesdays through Saturdays and 1 to 5 p.m. Sundays. Admission is $12 for adults, $11 for senior citizens, and $6 for children ages 6 to 17. Call 724-587-3412.

Heinz History Center, 1212 Smallman St., holds the third annual Hometown — Homegrown food expo from 10 a.m. to 3 p.m. Saturday. Activities and food samples are included with admission of $15 for adults, $13 for senior citizens, $6 for students and children ages 6 to 17, and free for children 5 and younger. “Pittsburgh’s Lost Steamboat: Treasures of the Arabia” continues. Visit www.heinzhistorycenter.org.Fort Pitt Museum in Point State Park each Saturday through Aug. 30 will host Summer Saturdays at the Fort, which is included in the admission of $6 for adults, $5 for senior citizens, and $3 for children ages 6 to 17, students and the military. Visit www.heinzhistorycenter.org.Phipps Conservatory and Botanical Gardens hosts the summer flower show with themed railroad displays through Oct. 5. Hours are 9:30 a.m. to 5 p.m. daily and until 10 p.m. Fridays. Admission is $15 for adults, $14 for senior citizens and students, and $11 for children ages 2 to 18. Visit phipps.conservatory.org.National Aviary, 700 Arch St., presents “Taking Flight: An Aerial Adventure” daily at 11 a.m. and 2 p.m. in the rose garden. Admission is $14 for adults, $13 for senior citizens and $12 for children. Hours are 10 a.m. to 5 p.m. daily. Visit www.aviary.orgToonSeum, 945 Liberty Ave., hosts an exhibit about the children’s book series “Little Golden Books” through June 30. Admission is $6 for those over age 13 and $3 for children ages 6 to 12. Senior citizens, college students, veterans and active military pay $5. Visit toonseum.org.Children’s Museum, 10 Children’s Way, Allegheny Square, hosts “XOXO: An Exhibit About Love and Forgiveness” through Aug. 31. Hours are 10 a.m. to 5 p.m. daily. Admission is $13 for adults and $12 for senior citizens and children ages 2 to 18. Visit www.pittsburghkids.org.Carnegie Museum of Natural History, 4400 Forbes Ave., Oakland, presents “Race: Are We So Different?” through Oct. 27. Visit www.carnegiemnh.org.Carnegie Science Center, North Side, hosts the Blue! exhibit through Jan. 1. Tickets are available for the center’s Fireworks Blowout, featuring four floors of hands-on exhibits, an Omnimax movie, laser show and refreshments from 6 to 11 p.m. July 4. Cost is $39. Call 412-237-3400.