Old Stone House will be the site of events for Halloween on Friday and Saturday and Oct. 30 and 31. "Spooky Stories," a family friendly tour featuring ghost storytelling, historical reenactments and paranormal investigation, will run from 5:30 to 7:30 p.m. Then from 8 to 10 p.m., a haunted house benefiting the Unionville Fire Department will be a bit scarier than the earlier event. Admission to Spooky Stories is free, though a $3 donation is suggested. The Haunted House is a fundraiser for the Unionville Fire Department and has an admission fee of $5. Concessions will be available. The Old Stone House, owned and managed by Slippery Rock University, is at the intersection of Routes 8, 173 and 528. Call 724-738-4964.

Harmony Museum on Mercer Street in Harmony offers guided tours from 1 to 4 p.m. daily except 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>Carnegie Science Center</B>, One Allegheny Ave., North Side, will help visitors learn about the elements and other chemistry concepts at ChemFest on Friday and Saturday. Visitors will get up close with some of childhood's beloved chemistry creations, like slimy oobleck, glow-in-the-dark cookies, and superballs. The center will be closed on Sunday because of the Steelers home game. The center will also be closed on Nov 15, and Dec. 6, 20 and 27 for the same reason. Hours are 10 a.m. to 7 p.m. Fridays and Saturdays and from 10 a.m. to 5 p.m. Sundays through Thursdays; closed holidays. Admission is $14 for adults and $10 for senior citizens age 62 and older and children 3 to 12. Parking is $3. Call 412-237-3400 or visit the Web site, www.carnegiesciencecenter.org.<B>National Aviary</B>, 700 Arch St., will host a Haunted Aviary for adults only from 7 to 10 p.m. Friday. Built on the site of the former Western Pennsylvania Penitentiary, the National Aviary has been said to be haunted. Guests will hear tales of aviary apparitions as well as ghost stories of the North Side. Light refreshments will be served. Cost is $25 per person. Call 412-323-7235, Ext. 213, to order tickets. Owl-O-Ween will be held from 11 a.m. to 3 p.m. Saturday and Sunday and Oct. 31 and is free for children 11 and younger in costume. Fall/winter hours are from 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>Pittsburgh Children's Museum</B>, 10 Children's Way, Allegheny Square, will host a Halloween costume parade at noon Oct. 28 to 31, explore makeup design from 10 a.m. to 4 p.m. Oct. 28 to 31, put on a puppet show, "Haunts, Hoots & Howls!" by We're Holden Puppets and a make your own monster puppet event at 1, 2 and 3 p.m. Oct. 31. Museum hours are 10 a.m. to 5 p.m. Mondays to Saturdays; and noon to 5 p.m. Sundays. Admission is $11 for adults; $10 for senior citizens and children ages 2 to 18, and free for children younger than 2. Call 412-322-5058 or visit the Web site, www.pittsburghkids.org.<B>Heinz History Center</B>, 1212 Smallman St., is showing "Behind the Scenes with the Pittsburgh Steelers: Photographs by Mike Fabus" through January. 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>Phipps Conservatory and Botanical Gardens</B> in Schenley Park continues "Life in the Gardens: Fräbel Glass at Phipps" through January. This exhibit features the work of German-born artist Hans Godo Fräbel, a founding father of modern glass sculpture. Phipps is open daily from 9:30 a.m. to 5 p.m. and until 10 p.m. on Fridays. Admission rates are $10 for adults, $9 for seniors age 62 and older and students with ID, and $7 for children ages 2 to 18. Phipps members and children younger than 2 are admitted free. Call 412-622-6914 or visit www.phipps.conservatory.org.