Part of the under­ground funic­u­lar “Tünel” on the north­ern shore of the Gold­en Horn in Istan­bul. The line con­nects two sta­tions — the low­er “Karaköy” (1.15 m above sea lev­el, Arap-Cami dis­trict, Bey­oğlu munic­i­pal­i­ty) and the upper “Bey­oğlu” (62.7 m above sea lev­el, Saşku­lu dis­trict, Bey­oğlu munic­i­pal­i­ty).