A celebration of the Delaware River returns Saturday, Sept. 21, as Trenton River Days offers an opportunity for fun, exercise, and education. South River Walk, the largest unofficial classroom in Trenton, hosts a free event that acknowledges the history, cultural, and recreational benefits of the Delaware River. The 11 a.m. to 3 p.m. event, located near Trenton Thunder Park on Route 29, offers an interesting day outdoors that features canoe and boat rides, food, live music, hayrides, fly fishing demonstrations with Trout Unlimited, crafts, and other fun. This will be an in-person event with educational games and exhibits for hands-on fun as The Watershed Institute will be on site to support various learning opportunities. Watershed staff will have large tanks filled with varieties of fish that inhabit the Delaware River. Guests also can explore the water quality of local waterways and learn how the data is gathered and used. Trenton River Days receives co-sponsorship by Mercer County Park Commission , Mercer County, New Jersey, The Watershed Institute, the City of Trenton NJ – City Hall, Alliance for Watershed Education of the Delaware River, Tulpehaking Nature Center, Friends for the Abbott Marshlands, and Artworks Trenton. The Watershed Institute is located at 31 Titus Mill Road, Pennington, N.J., 08534. (609) 737-3735.