Chicago 'L'

The Chicago subway is the second oldest and third busiest in the United States. But it's really famous because it doesn't merely run underground. Many of the lines tower over the streets on asphalt structures twenty feet high. It has become a symbol of the city and has been made famous in numerous movies and video games. Al Capone and his gangster friends have passed under these rails on our screens so many times. But although we'd seen it countless times, it still came as a surprise to see it in real life. When a train passes, the rattling is deafening, and you can't help but feel that the structure is about to collapse...but it doesn't, of course, and the locals don't even seem to notice the noise.