Wakhijir Pass

The Wakhjir Pass, also spelled Vakhjir Pass, is a mountain pass in the Hindu Kush or Pamirs at the eastern end of the Wakhan Corridor, the only potentially navigable pass between Afghanistan and China in the modern era. It links Wakhan in Afghanistan with the Tashkurgan Tajik Autonomous County in Xinjiang, China, at an altitude of 4,923 metres, but the pass is not an official border crossing point. With a difference of 3.5 hours, the Afghanistan–China border has the sharpest official change of clocks of any international frontier. China refers to the pass as South Wakhjir Pass, as there is a northern pass on the Chinese side.

Source: Wikipedia