The highest point on the Qinghai–Tibet Railway is 5,072 meters above sea level.
This record occurs at Tanggula Pass, on the railway between Golmud in Qinghai Province and Lhasa in Tibet. Track-laying reached the railway’s highest point on 24 August 2005, during construction of the difficult Golmud–Lhasa section. The line was formally completed in 2006 after years of work across frozen ground, thin air, and severe winter conditions.
The railway is often described as the world’s highest railway. A common mix-up is confusing the highest point of the track with Tanggula railway station, which stands at about 5,068 meters and is the world’s highest railway station. The line also includes the Fenghuoshan Tunnel, whose elevation is about 4,905 meters, making it one of the world’s highest rail tunnels.
The railway’s permafrost engineering is a major part of its story. Designers used embankments, cooling measures, and specially developed foundations to limit thawing beneath the track, because unstable frozen soil could shift when warmed.