Line Route Opened Length Stations Notes[27] Yenikapı ↔ Atatürk Airport / Kirazlı 1989[28] 26.1 km[28] 23[28] The 0.7 km extension to Yenikapi opened on 9 November 2014.[29] Operates from 06:00 a.m. to 00.00 a.m. Yenikapı ↔ Hacıosman 2000[30] 23.5 km[30] 16[30] Southern extension (3.5 km stretch to Yenikapı, with 3 stations) completed in February 2014. Operates from 06:15 a.m. to 00.00 a.m.