Take a thrilling 800-foot ride down the Mount Hoy tubing hill at Blackwell Forest Preserve. It's open on weekends and school holidays when there's plenty of snow (usually more than 3 inches). Rentals end at 3:30 p.m., although the hill may close early due to extreme cold or severe weather. Inner tube rentals are at the base of the hill and are $10 per tube per day. Pay with cash or credit card. Only District inner tubes are allowed.