A free outdoor discovery program, hosted by the Butler County Parks and Recreation Department, will feature “Our Own Down Under — Pennsylvania Animals Underground” at 7 p.m. today in the Carousel Shelter at Alameda Park. “How Does Your Garden Grow?” is planned for Aug. 15.

Moraine State Park hosts “History at the Hollow” from 9 a.m. to 5 p.m. Saturday. Activities will include Pennsylvania Dutch recipes prepared outdoors and tours the 200-year-old Davis Hollow Cabin at the end of North Shore Drive. Historic oil well operation will be demonstrated on Park Road from 10 a.m. to 4 p.m. Saturday and Sept. 14 and Oct. 12. Call 724-368-8811.

August star parties, sponsored by the Amateur Astronomers Association of Pittsburgh, will begin about 8:25 p.m., weather permitting, Friday and Saturday at the Nicholas E. Wagman Observatory in Deer Lakes Regional Park near Russellton. Call 724-224-2510.McConnells Mill State Park in Slippery Rock Township, Lawrence County, will host “A Taste of History: Dutch Oven Cooking” from noon to 3:30 p.m. Sunday. Park at Kildoo picnic area and hike down to the old mill. Mill Cleanup Day will be Aug. 17. The mill is open from 11 a.m. to 4 p.m. Fridays, Saturday and Sundays through October. Tours, which last about 45 minutes, are available at 1 and 3 p.m. Fridays, Saturdays and Sundays. Call 724-368-3612.