Line 12, also known as MetroSur (Spanish for MetroSouth), is a line of the Madrid Metro inaugurated on 11 April 2003. Line 12 is a circle line that is not in the city of Madrid, but links five suburban towns south of Madrid, serving around one million people. The towns linked by Line 12 are Alcorcón, Leganés, Getafe, Fuenlabrada and Móstoles. Despite parts of the line running through uninhabited territory, there are no above-ground sections in an effort to facilitate future urban development. At a total length of 40.6 km, it is the longest line in the network and even more extensive than Lines 9 and 10 with their appendages to the north and south. Despite this, Line 12 accumulated only about 32 million trips in 2018, down from 34.8 million in the previous year, making it the only line to lose users in that time and the third least used after the yet-to-be-completed Line 11 and the airport connection Line 8. This decrease was mainly caused by renovation works necessitating the temporary closure of sections of the line. From Wikipedia
