The Fenghuoshan 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 Qinghai–Tibet Railway, linking Qinghai and Tibet that was completed in 2006.
The tunnel is located in the western, sparsely populated Zadoi County, Qinghai (the eastern edge of the Hoh Xil mountainous region between the Kunlun and Tanggula mountain ranges).
Fenghuoshan Tunnel, constructed by China Railway Construction Corporation Limited (CRCC), opened to traffic on Oct 19, 2002.
The builders' overcoming of the technical difficulties presented by the plateau's frozen soil was evaluated by the Ministry of Science and Technology as one of the top ten scientific and technological events in China in 2002.
According to en.sasac.gov.cn