Harmony Museum on Mercer Street in Harmony is open from 1 to 4 p.m. daily; closed Mondays and holidays. Reservations are suggested for weekends and required for groups. Call 724-452-7341 or 888-821-4822, or visit the Web site, www.harmonymuseum.org.

<B>Pittsburgh Children's Museum,</B> 10 Children's Way, Allegheny Square, continues "Yinz Play!" through June 6. Live demonstrations on the highwire will be presented in "Slackline Pittsburgh" from noon to 3:30 p.m. Saturday. Regular hours are 10 a.m. to 5 p.m. Mondays to Saturdays; and noon to 5 p.m. Sundays, except holidays. Admission is $11 for adults; $10 for senior citizens and children ages 2 to 18, and free for children younger than 2. Parking is $5 for nonmembers. Call 412-322-5058 or visit the Web site, www.pittsburghkids.org.<B>Carnegie Science Center</B>, One Allegheny Ave., North Side, hosts "King Of Pop," a 45-minute laser show synchronized to the music of Michael Jackson, regularly at 9 p.m. Fridays and Saturdays. Weekday matinees are shown at 3 p.m., while Saturday and Sunday matinee shows start at 1 and 3 p.m. Science center hours are 10 a.m. to 7 p.m. Fridays and Saturdays and 10 a.m. to 5 p.m. Sundays through Thursdays; closed holidays. Regular admission is $14 for adults and $10 for senior citizens age 62 and older and children 3 to 12. Parking is $5. Call 412-237-3400 or visit the Web site, www.carnegiesciencecenter.org.<B>ToonSeum</B>, Pittsburgh's Museum of Cartoon Art at 945 Liberty Ave., will host a Toon In Series Anime Weekend on Friday, Saturday and Sunday. Tekkoshocon, Pittsburgh's long-running Japanese Animation and Culture Convention, is taking place today through Sunday at the David L. Lawrence Convention Center. Films will include "Pom Poko" at 7 p.m. Friday, "The Girl Who Leapt through Time" at 5:30 p.m. Saturday and "Barefoot Gen" at 4:30 p.m. Sunday. Admission is free, though donations are accepted. Regular museum hours are 10 a.m. to 3 p.m. Wednesdays and Thursdays, 10 a.m. to 5 p.m. Fridays and Saturdays and 11 a.m. to 4 p.m. Sundays, except holidays. Admission is $4 for adults and $3 for children ages 5 to 17; children younger than 5 are admitted free. Visit the Web site, www.toonseum.org.<B>National Aviary</B>, 700 Arch St., has opened its newest free-flight space, Grasslands. Earth Day activities are planned for April 22, and a "Party for the Planet" will take place from 11 a.m. to 2 p.m. April 24. Regular aviary hours are 10 a.m. to 5 p.m. Mondays through Saturdays and noon to 5 p.m. Sundays. Admission is $10 for adults; $9 for senior citizens; $8.50 for children ages 2 to 12; and free for children younger than 2. Call 412-323-7235 or visit the Web site, www.aviary.org.<B>Heinz History Center</B>, 1212 Smallman St., continues through July 18 "Discover the Real George Washington: New Views from Mount Vernon," an exhibition from George Washington's Mount Vernon Estate & Gardens. The exhibition features highlights from Mount Vernon's collection. Visitors can view nearly 100 objects, including full-scale figures of Washington, architectural models, decorative and fine art items, maps, manuscripts and paintings. History center hours are 10 a.m. to 5 p.m. daily, except holidays. Admission is $10 for adults, $9 for senior citizens age 62 and older, $5 for students with ID and for children ages 4 to 17, and free for children 3 and younger. Call 412-454-6000.<B>Carnegie Museum of Natural History</B>, 4400 Forbes Ave. in Oakland, continues the traveling exhibition "Whales/Tohora" through May 2. Museum hours are 10 a.m. to 5 p.m. Tuesdays through Saturdays, with additional hours until 8 p.m. Thursdays, and noon to 5 p.m. Sundays. Closed major holidays. Admission, which includes the Carnegie Museum of Art, is $15 for adults, $12 for senior citizens, and $11 for students and children age 3 and older, and free for members and children younger than 3. Call 412-622-3131 or visit the Web site, www.carnegiemnh.org.