Tünel has been carrying passengers up the same steep hillside since 1875, making it the second-oldest underground urban railway in the world after London's. French engineer Eugène-Henri Gavand dreamed it up after watching crowds trudge up the slope between the waterfront at Karaköy and the heights of Pera. Rather than cut a road, he bored a tunnel and let a steam-driven cable haul two counterweighted cars past each other in the dark. The line climbs roughly sixty metres in barely half a kilometre, so the whole journey lasts about ninety seconds.
You step into a compact carriage, wood-trimmed and painted the deep colours of an old railway, and the doors close on a curved platform tucked below the street. The car tilts with the grade, tunnel walls sliding past the windows, and before you have settled you reach the far end. At the top the door opens a few steps from the southern end of İstiklal Avenue and its red nostalgic tram; at the bottom you surface near Galata. Locals still ride it as an everyday shortcut, so you travel alongside commuters rather than only sightseers.