The Atal Tunnel carries the Manali road under the Rohtang Pass into Lahaul-Spiti
Background
The Atal Tunnel is a 9.02 Km long highway tunnel that connects Manali to the Lahaul-Spiti valley in Himachal Pradesh throughout the year.
Before it was built the valley was cut off for about 6 months each year owing to heavy snowfall.
The tunnel is built in the Pir Panjal range of the Himalayas at an altitude of 3000 Mtrs, that is 10,000 Feet, from Mean Sea Level.
It reduces the road distance by 46 Kms between Manali and Leh and the travel time by about 4 to 5 hours.
It carries semi transverse ventilation, SCADA controlled fire fighting, illumination and monitoring systems, and an emergency egress tunnel built into the main tunnel itself.
The tunnel was constructed by the Border Roads Organisation and runs under the Rohtang Pass on the Manali - Leh Highway, and it has been certified by World Book of Records as the World's Longest Highway Tunnel above 10,000 Feet.
In plain words
BRO Border Roads Organisation — The road construction force that builds and maintains roads in India's border areas.
Pir Panjal Pir Panjal range — An outer Himalayan range running through Himachal Pradesh and beyond.