A northern extension from 4th Levent to Atatürk Oto Sanayi station in Maslak (Ayazağa) entered service in 2009, as well as a southern extension from Taksim to Şişhane station in Beyoğlu, near the northern entrance of Tünel. Last northern extension for short term, Hacı Osman was opened in 2011. The rest of the southern section of the metro, which will run to Yenikapı, across the Golden Horn on a bridge and underground through the old city, is also under construction. The southern extension of M2 from Şişhane to Yenikapı over the new Golden Horn Bridge is opened in 2013 permitting the line to reach the Yenikapı Transfer Center. Finally the Airport (M1A) and Bağcılar (M1B) lines' eastern terminus was extended from Aksaray to this transfer center in 2014.