The Castlewood State Park is a state park and recreation area in Ballwin, Missouri. It is best known for its recreation opportunities.

Established in 1974, the Castlewood State Park covers 1818 acres of land. The area has been in use since the early 1900s as a retreat venue by ?partying? St. Louis residents. The area was once filled with dance clubs, which in time returned to its natural state, providing a lush valley that is ideal for some outdoor adventure.

This massive site is most famous for its trails, which are perfect for hiking, horseback riding, and mountain biking. The site also has facilities for fishing, boating, swimming, and picnicking among other things. Thanks to its location near the city, the Castlewood State Park is a well visited destination.