The strategically important all-weather Atal Tunnel, the longest highway tunnel in the world, will be inaugurated by Prime Minister Narendra Modi today. The 9.02 km-long tunnel connects Manali to Lahaul-Spiti valley throughout the year. The inauguration will take place at 10 am today. It reduces the road distance by 46 kilometers between Manali and Leh and the time by about 4-5 hours. The Tunnel is built with ultra-modern specifications in the Pir Panjal range of Himalayas at an altitude of 3000 meters (10,000 Feet) from the Mean Sea Level (MSL).