Schedule a group adventure with jaw dropping, heart racing moments on Grafton Zipline Adventures - a zip line that affords those brave enough a stunning river view and hours of fun. It is one of the largest zip lines in Illinois. Open daily from 8 a.m. to 6 p.m. With seven zip lines offering various heights, lengths and speeds, there is a course to satisfy every thrill-seeker. The Treehouse Leap is the longest cable on the course. The Soaring Eagle reaches the highest point and if you're feeling really adventurous, the Creek Hopper is the fastest cable, reaching up to 45 mph during its run. Do all seven, only at Grafton Zipline!