F4 (Istanbul funicular)
The F4, officially referred to as the F4 Boğaziçi Üni./Hisarüstü–Aşiyan funicular line is an long funicular railway in Beşiktaş, Istanbul. When opened on 28 October 2022, it became the fourth funicular line in Istanbul as well as the longest, surpassing the F3 line by. The F4 line traverses a height difference of about and total travel time is estimated at 2 minutes and 30 seconds.
The line begins at Boğaziçi Üniversitesi station and heads east to Aşiyan along the Bosporus. It is connected to the M6 line at Boğaziçi Üniversitesi. The entrance to Boğaziçi Üniversitesi station is constructed next to the main entrance to Boğaziçi University.