The State Museum on West State Street is free and covers more ground than its civic-sounding name implies. The natural history collection includes a life-sized mastodon skeleton and substantial fossil collections. The fine art galleries hold American paintings from the 18th century to the present, with particular strength in New Jersey artists. The planetarium in the basement runs public shows on weekends.
It shares a block with the State House and the Old Barracks — plan to visit all three together. Open Tuesday through Sunday.