The Fenghuoshan railway tunnel is the highest railway tunnel in the world. It is 1,338 metres long, and stands 4,905 meters above sea level. It is part of the recently-completed Qingzang railway, linking China proper and Tibet. metre or meter, see meter (disambiguation) The metre is the basic unit of length in the International System of Units. ... The term above mean sea level (AMSL) refers to the elevation (on the ground) or altitude (in the air) of any object, relative to the average sea level. ... The Qingzang railway, Qinghai–Xizang railway, or Qinghai–Tibet railway (Simplified Chinese: 青藏铁路; Traditional Chinese: 青藏鐵路; pinyin: Qīngzàng Tiělù), is a railway which connects Xining, Qinghai Province, to Lhasa, Tibet Autonomous Region, in the Peoples Republic of China. ... China proper refers to the historical heartlands of China in the context of that paradigm which contrasts these heartlands with frontier regions of Outer China (including sections of Inner Asia and other regions). ... Tibet (older spelling Thibet; Tibetan: བོད་, Bod, pronounced pö in Lhasa dialect; Chinese: , pinyin: Xīzàng or Chinese: , pinyin: Zàngqū [the two names are used with different connotations; see Name section below]) is a region in Central Asia and the home of the Tibetan people. ...