The Chicago "L" (short for "elevated") is the rapid transit system serving the city of Chicago and some of its surrounding suburbs in the U.S. state of Illinois. It is operated by the Chicago Transit Authority (CTA). It is the fourth-largest rapid transit system in the United States in terms of total route length, at 102.8 miles (165.4 km) long and the second-busiest rail mass transit system in the United States, after the New York City Subway That´s what wikipedia says about it. Watch the "L" with the eyes of Wilhelm Kronenberg, a german amateur cameraman and engineer, showing us lots of fantastic views. Footage available for broadcasting and exhibitions. requests: [email protected]

Chicago's "L" provides 24-hour service on some portions of its network, being one of only five rapid transit systems in the United States to do so.[note 2] The oldest sections of the Chicago "L" started operations in 1892, making it the second-oldest rapid transit system in the Americas, after New York City's elevated lines.

The "L" has been credited with fostering the growth of Chicago's dense city core that is one of the city's distinguishing features.[6] The "L" consists of eight rapid transit lines laid out in a spoke–hub distribution paradigm focusing transit towards the Loop. Although the "L" gained its name because large parts of the system are elevated,[7][8] portions of the network are also in subway tunnels, at grade level, or open cut.[1]

In 2014, the "L" had an average of 752,734 passenger boardings each weekday, 486,267 each Saturday, and 359,777 each Sunday.[9] In a 2005 poll, Chicago Tribune readers voted it one of the "seven wonders of Chicago",[10] behind the lakefront and Wrigley Field, but ahead of Willis Tower (formerly the Sears Tower), the Water Tower, the University of Chicago, and the Museum of Science and Industry.