Question: The Iron Gate breaks up the mountains between Samarkand and a province which is 20 kilometers northwest of what provincial capital?
Sentence (from "Balkh"): Balkh ( ; Persian/Pashto: بلخ‎ "Balkh"; Bactrian: βαχλο, "ẞaxlɔ") is a town in the Balkh Province of Afghanistan, about 20 kilometers northwest of the provincial capital, Mazar-e Sharif, and some 74 km south of the Amu Darya river.
Relevant evidence: Yes