The 9.02 km-long horseshoe-shaped single-tube, two-lane tunnel -- the world's longest motorable tunnel at over 3,000 metre above the sea level, came up under the 3,978 metre Rohtang Pass in the Pir Panjal range some 30 km from here in Himachal Pradesh. The tunnel connects this tourist resort to the Lahaul Valley throughout the year. Earlier, the valley was cut off for about six months each year owing to heavy snowfall and snapping of road link via the Rohtang Pass.