Natural areas are open from dawn to dusk daily.
Marian R. Byrnes Park, previously known as Park No. 562 or Van Vlissingen Prairie, is located in the Jeffery Manor neighborhood. At approximately 135 acres, it is one of the largest natural areas in Chicago. The site includes marsh, wet prairie, prairie, savanna, and woodland and is a great place to observe wildlife including frogs, snakes, birds, and deer.