The San Diego Council of Hostelling International will hold its 37th annual Midnight Madness Fun Bicycle Ride through scenic San Diego at midnight on Saturday, Aug. 21. The 18-mile route is primarily flat and starts at the San Diego County Administration Building at 1600 Pacific Highway before winding through Harbor Island, Shelter Island, Old Town and downtown. Each registered cyclist will receive a T-shirt, chances to win prizes and safety support along the route. Alaska Airlines and REI will sponsor a costume contest for the more zany participants. The entry cost is $30 before or $35 the night of the event, and proceeds will help support education and outreach programs for the non-profit organization Hostelling International. To register for the ride or to find out more, visit www.sandiegohostels.org.