Carnegie Science Center next to Heinz Field on the North Side, hosts “Guitar: The Instrument That Rocked the World” through Sept. 30. This fully immersive touring exhibition of The National Guitar Museum explores the history and science of creating sound with wood and steel. The exhibition contains more than 60 instruments, hands-on interactives, models, touch screens, performance video, audio and photographs. Admission to all parts of the exhibit is free with general admission to the Science Center, which is $17.95 for adults and $11.95 for children ages 3 to 12. Science Center hours are 10 a.m. to 7 p.m. Saturdays and 10 a.m. to 5 p.m. Sundays through Fridays. Call 412-237-3400.

National Aviary, 700 Arch St., has opened a new burrowing owl exhibit that shows the baseball-sized owls, native to the western United States and South America, in their underground burrows. Also open is “Parrots of the Caribbean” in the Helen M. Schmidt FliteZone Theater, and the aviary's rooftop Sky Deck theater features birds of prey in free-flight demonstrations. The public can view the newly hatched African penguin chicks twice daily at 11 a.m. and 2:30 p.m. at the Penguin Point exhibit. The aviary is open daily from 10 a.m. to 5 p.m. Admission is $13 for adults, $12 for senior citizens, $11 for children ages 2 to 18, and free for children younger than 2. Call 412-323-7235 or visit www.aviary.org.

Phipps Conservatory and Botanical Gardens at One Schenley Park presents its summer flower show “Fountains of Youth” through Sept. 30. Visitors can explore the healing powers of plants along with the soothing sights and sounds of fountains and bright blooms. Phipps is open daily from 9:30 a.m. to 5 p.m. and until 10 p.m. Fridays. Admission costs $12 for adults; $11 for senior citizens age 62 and older and students with ID; $9 for children ages 2 to 18; and free for children younger than 2. Call 412-622-6914 or visit phipps.conservatory.org.

ToonSeum, Pittsburgh's Museum of Cartoon Art at 945 Liberty Ave., presents “Pearls Before Swine: The Art of Stephan Pastis” Friday through Sept. 30. The exhibition will open with a visit from Stephan Pastis at 7 p.m. Friday and at noon Saturday. Tickets are available for the lecture at www.pittsburghpearls2.eventbrite.com. Call 412-232-0199 or visit www.toonseum.org.

Children's Museum, 10 Children's Way, Allegheny Square, presents “The Wizard of Oz Children's Educational Exhibition” through Sept. 2. Regular museum hours are 10 a.m. to 5 p.m. Mondays to Saturdays and noon to 5 p.m. Sundays; closed holidays. Admission prices are $12 for adults, $11 for children ages 2 to 18 and senior citizens, and free for children younger than 2. Parking is $5; on-street, metered parking also is available. Call 412-322-5058 or visit www.pittsburghkids.org.