Mapo District is one of the 25 districts of Seoul, South Korea.

Seoul Subway Line 2, also known as the Circle Line, is a circular line of the Seoul Metropolitan Subway. The line running clockwise is called the "inner circle line" and the counter-clockwise line is called the "outer circle line". This is Seoul's most heavily used line, and consists of the main loop, the Seongsu Branch and the Sinjeong Branch for a total line length of 60.2 km (37.4 mi). The Line 2 loop is the third longest subway loop in the world after Moscow Metro Bolshaya Koltsevaya line and Beijing Subway Line 10. In 2019, Line 2 had an annual ridership of 812 million passengers or 2.2 million passengers per day.