Zelienople Historical Society will host its 22nd annual Christmas Home Tour on Saturday. Homes decorated in a variety of styles will be open for guests during the self-drive event that begins at 9 a.m. The $22 ticket price includes the tour and a catered luncheon featuring door prizes. Paid reservations are required in advance. Call 724-452-9457.

The annual holiday train display at Thorn Creek United Methodist Church, 142 Rockdale Road, Jefferson Township, opens today and continues through Jan. 4. Hours are 4 to 8 p.m. Fridays and noon to 8 p.m. Saturdays and Sundays. Extended hours are planned for Dec. 28 through Jan. 4, when the display will be open from noon to 8 p.m. Soups, sandwiches, snacks and refreshments will be available. Check thorncreekumchurch.org for cancellations due to weather.

Harmony Museum, 218 Mercer St., Harmony, has unveiled the Christmas season model railroad display and extended indefinitely a Flags of Freedom exhibit. Guided tours are offered 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.

Carnegie Science Center, North Side, has opened the Miniature Railroad & Village with its new addition, a model of the Buhl Planetarium & Observatory. Lionel Days continue through Jan. 1, and Locomotion Weekend will be Dec. 13 and 14. The center continues the exhibit “Blue!” through Jan. 1. Hours are 10 a.m. to 7 p.m. Saturdays and 10 a.m. to 5 p.m. Sundays through Fridays. General admission is $17.95 for adults and $11.95 for children ages 3 to 12. Visit CarnegieScienceCenter.org.Phipps Conservatory and Botanical Gardens, 700 Frank Curto Drive, hosts the winter flower show through Jan. 11. Additionally, Phipps and Pittsburgh Ballet Theatre will present the Sugarplum Fairy, 30-minute creative movement classes for children of all ages, at 10:30 a.m. Saturday and Dec. 13, free with Phipps admission, which is $15 for adults; $14 for students and seniors; and $11 for children ages 2 to 18. Call 412-622-6914.National Aviary, 700 Arch St., presents “Wings in Winter” daily holiday activities, festive décor and a new, musical free-flight bird show through Jan. 11. Admission is $14 for adults, $13 for senior citizens and $12 for children ages 2 to 18. Hours are 10 a.m. to 5 p.m. daily. Visit www.aviary.orgHeinz History Center, 1212 Smallman St., hosts “Pittsburgh's Lost Steamboat: Treasures of the Arabia” through Jan. 4. An exhibition showcasing the Heinz company also continues. Admission is $15 for adults, $13 for senior citizens, and $6 for children ages 6 to 17. Visit www.heinzhistorycenter.org.ToonSeum featuring cartoon art at 945 Liberty Ave., presents “When Universes Collide: The Ultimate Superhero Smackdown” through Jan. 4. Admission is $6 for those over 13 and $3 for children 6 to 12. Senior citizens, college students, veterans and active military pay $5. Visit toonseum.org.Children's Museum, Allegheny Square, hosts the exhibit “Bounce: Inspired by the World's Most Amazing Ball!” through Feb. 1. Admission is $14 for adults and $13 for children ages 2 to 18 and senior citizens. Hours are 10 a.m. to 5 p.m. daily. Visit www.pittsburghkids.org.