h/t 50 Days After
[WP] There are many theories attempting to explain İstanbul's etymology. One widely accepted theory states that, İstanbul (Turkish pronunciation: [isˈtanbuɫ], colloquially [ɯsˈtambuɫ]) derives from the Medieval Greek phrase "εἰς τὴν Πόλιν" [is tin ˈpolin] or, in the Aegean dialect, "εἰς τὰν Πόλιν" [is tan ˈpolin] (Modern Greek "στην Πόλη" /stin ˈpoli/), which means "in the city" or "to the city". In modern Turkish, the name is written "İstanbul", with a dotted İ, as the Turkish alphabet distinguishes between a dotted and dotless I. Also, while in English the stress is on the first syllable ("Is"), in Turkish it is on the second syllable ("tan"). Like Rome, Istanbul has been called "The City of Seven Hills" because the oldest part of the city is supposedly built on seven hills, each of which bears a historic mosque.