One of the common Turkish words missing an exact translation in English is yokuş (yokush). It means a steep road or path. None of the English words offered by From Language to Language, including, rise, ascent, slope, incline, ramp, climb, conveys the Turkish meaning of yokuş that it is specifically a road, not just a steep slope on the side of a hill.
Istanbul, having been built on a very hilly territory, naturally has many steep roads. One of them is known as Portakal Yokuşu, the "Yokuş of Oranges", a segment of the long and winding climb, officially known as Adnan Saygun Street, that starts out in Ortaköy, passes under the Bosphorus Bridge and ends in the district known as Ulus.
I had walked up and down that street many times, but not seen any orange trees along it. So the origin of its name was a mystery until my last trip to Istanbul last month when the surprising identities of the trees lined up in a narrow median strip along one section of the road were revealed: osage oranges (Maclura pomifera).
The original range of the osage orange covered a relatively small area in southern U.S., but its range has been artificially widened by introductions to over much of the U.S. For example, they are quite common along the C&O Canal. According to a Turkish book* on the trees of the Marmara region of Turkey, osage oranges are grown in Turkey as ornamental and hedge trees.
I strongly suspect Portakal Yokuşu was named after the osage oranges, but at the moment I don't have any historical data for support.
*Tuğrul Mataracı, Ağaçlar: Marmara Bölgesi doğal-egzotik ağaç ve çalıları, 2004.