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

Carnegie Museum of Natural History, 4400 Forbes Ave., Oakland, is displaying its decorated holiday trees, six fresh 20-foot Colorado spruce trees with the theme “Embracing the Art of Play,” through Jan. 12. The Neapolitan presepio Italian Nativity scene is on view through Jan. 9. Museum hours are 10 a.m. to 5 p.m. Tuesdays to Saturdays, with extended hours until 8 p.m. Thursdays, and noon to 5 p.m. Sundays. The museum will be closed Wednesday and Jan. 1. Admission is $17.95 for adults, $14.95 for senior citizens, and $11.95 for students and children ages 3 to 18. Admission after 4 p.m. Thursdays is discounted. Call 412-622-3131 or visit www.carnegiemnh.org.National Aviary, 700 Arch St., welcomes a new pair of Andean Condors in the outdoor exhibit. Another exhibit, “Canary’s Call,” showcases four signature bird species and a number of others. The interactive free-flight show “Beaks!” runs daily at 11 a.m. and 3 p.m. through Jan. 1; this show is $5 in addition to the cost of admission, which is $13 for adults, $12 for senior citizens, $11 for children ages 2 to 18, and free for children younger than 2. Regular hours are 10 a.m. to 5 p.m. daily, but the aviary will be closed Tuesday and Wednesday and will close at 3 p.m. Dec. 31. Call 412-323-7235 or visit www.aviary.org.Children’s Museum, 10 Children’s Way, Allegheny Square, will be closed Wednesday and Jan. 1. Extended holiday hours are 9 a.m. to 5 p.m. Dec. 26 to 31. Regular hours are 10 a.m. to 5 p.m. daily. The exhibit Tape Scape, a massive indoor landscape made of 360 rolls (that’s 22 miles!) of packing tape, continues through Jan. 19. “Tough Art” concludes Dec. 31. Admission is $13 for adults, and $12 for children ages 2 to 18 and senior citizens. Call 412-322-5058 or visit www.pittsburghkids.org.Carnegie Science Center, North Side, presents Lionel Days, a month-long festival of trains, through Jan. 1. The miniature railroad display is free with general admission, which is $17.95 for adults and $11.95 for children ages 3 to 12. Call 412-237-3400.Heinz History Center, 1212 Smallman St., hosts “Poptastic!” focusing on Pittsburgh artist Burton Morris and more than 100 original works of art through Feb. 23. The exhibit “Pennsylvania’s Civil War” continues through Jan. 5. Center admission is $15 for adults, $13 for senior citizens, and $6 for students and children ages 6 to 17. Call 412-454-6000 or visit www.heinzhistorycenter.org.