All right, back after a long hiatus. I just happened to visit this engineering marvel in the first snowfall of the season last week.
Atal Tunnel is built on NH3 highway to provide access to Lahual-Spiti district in Himachal Pradesh throughout the year bypassing the existing Rohtang La which remains closed for more than half a year because of heavy snowfall in the high mountain pass.
This tunnel is a little more than 9 kms in length and is the longest road tunnel above 10,000 feet in the world and reduces the travel time to Keylong and Leh by 4 to 5 hours.
Some glimpses of the journey in the video below.
ShySnail 