A place in Chicago has been designed to keep witnesses to crimes safe. Some think the "safe site" is inside the Metropolitan Correction Center. Others claim it's in an old Cold War bunker in Lincoln Park. But only a select few know the answer.
Click on the video above to get the full story.
Officials confirmed the site's existence at a trial several years ago.
Hidden Chicago is an exclusive abc7 series uncovering secrets of Chicago. Click here to watch more stories.
Hidden Chicago: A safe site