Hải Vân Pass

Overview

The Hải Vân Pass crosses over a spur of the Trường Sơn (Annamite) Range that emerges from the west and juts into the South China Sea, forming the Hải Vân Peninsula and the adjoining Son Tra Island. The pass, which once formed the boundary between the kingdoms of Đại Việt and Champa, also forms a boundary between the climates of northern and southern Vietnam, sheltering the city of Da Nang from the "Chinese winds" that blow in from the northwest. During the winter months (November–March), for instance, weather on the north side of the pass might be wet and cold, while the south side might be warm and dry.
The pass is renowned for its scenic beauty. Presenter Jeremy Clarkson, host of the BBC motoring programme Top Gear, featured the pass during the show's 2008 Vietnam Special, calling the road "a deserted ribbon of perfection—one of the best coast roads in the world."

History

Hải Vân Pass has been of major strategic importance in this history of Vietnam, and for a long time represented a major barrier to any land army that attempted to move between the northern and central regions of the country.
During the 1st century A.D., the Chinese general Ma Yuan (Mã Viện), after pacifying northern Vietnam, advanced south and established the southern border of the Han (Hán) empire by setting up columns of bronze, possibly at Hải Vân.  Ma Yuan also left behind some Chinese military families to hold the frontier.  When the Han empire collapsed at the end of the 2nd century, the local kingdom of Linyi (Lâm Ấp), the predecessor to the medieval polity of Champa, was created by a petty frontier bureaucrat of the Han administration, probably in the area of modern Huế somewhat to the north.

Transport

The pass is crossed by two main transport routes: Vietnam's main north–south highway, National Route 1A, and the North–South Railway. The road crosses over the mountain more or less directly, climbing to an elevation of 496 m (1,627 ft) and passing south of the 1,172 m (3,845 ft) high Ai Van Son peak, while the railway hugs the coastline more closely, passing through a series of tunnels along the way. Since its opening in 2005, the Hải Vân Tunnel—the longest tunnel in Southeast Asia—offers an alternative road across the pass, reducing travel times by at least an hour.