Passavant House and Buhl House, historic house museums of the Zelienople Historical Society, at 243 and 221 S. Main St. in Zelienople, are now open for the season. Regularly scheduled tours begin at 1 and 2:30 p.m. Wednesdays and Saturdays through September. Admission, which covers both houses, is $5 for adults and $3 for students. Call 724-452-9457.

Butler County Heritage Center, 119 W. New Castle St., with the new exhibit of the Jay Bee Miniature Circus, will be open from noon to 4 p.m. Wednesdays and 9 a.m. to noon Fridays from May through August, excluding legal holidays. Admission is $3 for adults, $1 for children ages 5 to 17, and free for children younger than 5. Call 724-283-8116.

Lowrie-Shaw House, built in 1828 by Walter Lowrie, Butler's only U.S. senator, at 123 W. Diamond St., will be open through September from noon to 4 p.m. Mondays, Wednesdays and Fridays, except legal holidays. Admission is $3 for adults, $1 for children 5 to 17, and free for children younger than 5. Call 724-283-8116.

Harmony Museum, 218 Mercer St., Harmony, hosts its annual Herb & Garden Fair, offering an opportunity to exchange and purchase plants, from 9 a.m. to 3 p.m. Saturday at the museum's historic barn annex on Mercer Road, just north of Connoquenessing Creek. Admission is free. A homemade lunch will be available. Guided tours of three Harmony Museum buildings, including a mid-1800s log house, are available from 1 to 4 p.m. Admission is charged for the tour. Call 724-452-7341 or toll-free 888-821-4822, or send e-mail to hmuseum@zoominternet.net.

Cooper Cabin Pioneer Homestead, 199 Cooper Road in Cabot, will host a Needlecraft Day from 1 to 4 p.m. June 22. Continuous demonstrations are planned. Docent-tours of the cabin will be available. Admission is $3 for adults, $2 for children 5 to 17 and senior citizens, and free for children younger than 5. Call the Butler County Historical Society at 724-283-8116.

<B>Fort Pitt Museum</B> in Point State Park, 101 Commonwealth Place, will host an appearance by John Fea discussing his book at 1 p.m. Saturday. "The Way of Improvement Leads Home: Philip Vickers Fithian and the Rural Enlightment" is the first full-length biography of Fithian, a diary-writer and revolutionary patriot. Admission is $5 for adults, $4 for senior citizens 60 and older, $2 for children 6 to 17, and free for children 5 and younger. Call 412-281-9285.<B>Pittsburgh Zoo and PPG Aquarium</B>, 7340 Butler St., is open 9 a.m. to 6 p.m. for the summer. Admission through Nov. 30 is $12 for adults, $11 for senior citizens 60 and older, $10 for children 2 to 13, and free for children younger than 2. Parking is free. Call 412-465-2524 for information.<B>Rodef Shalom Biblical Botanical Garden</B>, 4905 Fifth Ave., exhibits "Land of Milk and Honey" with new plantings, displays and tours, through Sept. 15. The garden displays more than 100 temperate and tropical plants grown in ancient Israel. Hours are noon to 1 p.m. Saturdays and 10 a.m. to 2 p.m. Sundays through Thursdays, as well as 7 to 9 p.m. Wednesdays through August. Admission is free, as is parking. Call 412-621-6566.<B>National Aviary</B>, 700 Arch St., site of the free-flight bird show called FliteZone, hosts Little Peepers, the aviary's story-time program, at 10:30 a.m. Mondays. Two-Fur-Tuesdays offers two-for-one admission on Tuesdays through Aug. 26. Summer hours are now in effect and are 9 a.m. to 5 p.m. daily through Sept. 1. Free admission for dads will be offered on Father's Day, June 19. Regular admission is $9 for adults; $8 for senior citizens; $7.50 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., presents "Pittsburgh Recast," featuring more than 50 pieces of work by members of the Pittsburgh Society of Illustrators through Sept. 7. Hours are 10 a.m. to 5 p.m. daily, except holidays. Regular admission includes both the History Center and Sports Museum and is $9 for adults, $7 for senior citizens older than 61, $5 for students with ID and for children ages 6 to 18, and free for children younger than 6. Call 412-454-6000.<B>Carnegie Museum of Natural History,</B> 4400 Forbes Ave. in Oakland, has put on exhibit a life-size crystal skull, which has been locked away in the museum's mineral collection, in Hillman Hall of Mineral and Gems. The skull is being brought out in honor of the new "Indiana Jones and the Kingdom of the Crystal Skull" movie. "In Harmony with Nature II" by Donald M. Robinson, presenting more than 200 color photographs that portray the diversity of culture, wildlife, flora, and landscape of six continents and more than 60 countries, continues through Sept. 14. "Time Machines: Watches from the H.J. Heinz Collection" runs through July 6. Admission is $15 for adults, $12 for senior citizens, $11 for children ages 3 to 18 and full-time students with ID, and free to children younger than 3 and Carnegie Museums members. Hours are 10 a.m. to 5 p.m. Tuesdays through Saturdays, 10 a.m. to 8 p.m. Thursdays, noon to 5 p.m. Sundays, plus for the summer, from 10 a.m. to 5 p.m. Mondays as well. Call 412-622-3131 or visit the Web site, www.carnegiemnh.org.