Blue Line (CTA)
The Blue Line is a 26.93-mile-long (43.34 km) Chicago "L" line which runs from O'Hare International Airport at the far northwest end of the city, through downtown via the Milwaukee–Dearborn subway and across the West Side to its southwest end in Forest Park, with a total of 33 stations (11 on the Forest Park branch, 9 in the Milwaukee–Dearborn subway and 13 on the O'Hare branch). At about 27 miles, it is the longest line on the Chicago "L" system and second busiest, and one of the longest local subway/elevated lines in the world.