COUNTYThe Mega Cruise will be noon to 10 p.m. Saturday at the Butler County Airport, 475 Airport Road, hosted by the Penn Township Volunteer Fire Department. There is parking for more than 1,000 vehicles, and there will be music, food, raffles and an auction.A miniature railroad and village along with a model car and truck display is planned for noon to 5 p.m. Saturday and noon to 4 p.m. Sunday at Donaldson Motors, 714 River Ave., Emlenton. The HO scale train display covers a 30- by 18-foot area. Up to 11 trains run with more than 200 autos, trucks, buildings and trains featured. Call 724-867-2293.

PITTSBURGHHeinz History Center, 1212 Smallman St., will celebrate the 200th anniversary of the City of Pittsburgh’s incorporation in 1816 with the Pittsburgh Bicentennial Birthday Bash from 7 to 11 p.m. Friday. Visit www.heinzhistorycenter.org.National Aviary, 700 Arch St., presents the Butterfly Garden in the outdoor Rose Garden daily from 11 a.m. to 4 p.m. The garden is included with general admission of $14 for adults and $13 for senior citizens and children 2 to 12. Visit aviary.org.ToonSeum, a museum of cartoon art, 945 Liberty Ave., hosts “Captain America: 75 Years of the Sentinel of Liberty” through Aug. 14. Work by editorial cartoonists is on display through Aug. 28. Admission is $8 for those 13 and older and $4 for children 6 to 12. Military personnel and veterans receive free admission. Visit toonseum.org.Children’s Museum, Allegheny Square, presents “Daniel Tiger’s Neighborhood: A Grr-ific Exhibit” through Jan. 17. Hours are 10 a.m. to 5 p.m. daily. Admission is $14 for adults and $13 for children 2 to 18 and senior citizens. Visit www.pittsburghkids.org.Carnegie Museum of Natural History, 4400 Forbes Ave., Oakland, hosts the traveling exhibition “50 Greatest Photographs of National Geographic” through Sept. 11. Admission is $19.95 for adults, $14.95 for senior citizens, and $11.95 for children 3 to 18. Visit www.carnegiemnh.org.Carnegie Science Center, North Side, hosts “Tech Tours” of the USS Requin, the Cold War-era submarine moored along the Ohio River, on July 10 and 24. Center admission is $18.95 for adults and $11.95 for children 3 to 12. Center hours are 10 a.m. to 7 p.m. Saturdays and 10 a.m. to 5 p.m. Sundays through Fridays. Visit CarnegieScienceCenter.org.