The Metro is the rapid transit system serving Madrid as well as some suburbs. Founded in 1919, it underwent extensive enlargement in the second half of the 20th century. It is the second longest metro system in Europe (after London's) at . , it has 302 stations. Only the Métro of Paris has more stations. It features 13 lines; 12 of them are colour-coded and numbered 1 to 12 (Line 1, Line 2, Line 3, Line 4, Line 5, Line 6, Line 7, Line 8, Line 9, Line 10, Line 11 and Line 12), while the other one, the short ''Ramal'' (R), links Ópera to Príncipe Pío.