The State Museum occupies a large purpose-built building directly adjacent to the Capitol, and it covers Pennsylvania's natural and human history from the Cambrian period to the 20th century. The natural history galleries — with a planetarium, a full-scale mastodon skeleton, and extensive geology and mineralogy collections — are strong. The Pennsylvania military history collections span the French and Indian War through to World War II, with particular depth around the Civil War, in which Pennsylvania played a central role.
The museum also holds a significant collection of Pennsylvania German decorative arts, decorative furniture, and the works of the Brandywine painters (Howard Pyle, N.C. Wyeth). Entry is free on Tuesdays; otherwise a modest fee. The building is connected to the Capitol by an underground tunnel, which is handy on cold days and in summer heat. Plan for two hours minimum if you want to see the main collections.