Atal Tunnel (Hindi: अटल सुरंग) is a 9.02-kilometre-long (5.60 mi) road tunnel connecting Manali and Keylong, thus helping in bypassing the Rohtang Pass, Himachal Pradesh in the eastern Pir Panjal range of the Himalayas. It carries two lanes of National Highway 3 and is the longest highway single-tube tunnel above 10,000 feet (3,048 m) in the world. It is named after the former Prime Minister of India, Atal Bihari Vajpayee.
The tunnel reduces the travel time and overall distance between Manali and Keylong on the way to Leh. The route, which previously went through Gramphu, was 116 km (72.1 mi) long and took 5 to 6 hours in good conditions. The new route via the tunnel brings down the total distance travelled to 71 km (44.1 mi) which can be covered in about 2 hours, a reduction of around 3 to 4 hours when compared to the earlier route. Moreover, the tunnel bypasses most of the sites that were prone to road blockades, avalanches, and traffic snarls.