The Argonne National Laboratory, one of the Department of Energy's oldest and largest national labs, opens its doors to the public Saturday for a rare behind-the-scenes look.

There'll be more than 100 demos and activities, including taking a test drive in the Advanced Powertrain Research Facility's driving simulator, racing a robot in a molecular biology speed challenge, watching nanoparticles change colors, "fun with cryogenics," and much more. A free shuttle service will transport visitors around the facility and to and from parking areas. 9 AM-4:30 PM, 9700 S. Cass, 630-252-3751.