the line includes the tanggula pass, at 5,072 m (16,640 feet) above sea level the world's highest rail track and tanggula railway station which is the highest railway station. the 1,338 m fenghuoshan tunnel is the highest rail tunnel in the world, at 4,905 m above sea level. the 3,345-m yangbajing tunnel is the longest tunnel on the line. it is 4,264 m above sea level, 80 kilometres north-west of lhasa.