The Atal Tunnel changed the Himalayan road map. For generations, the road north from Manali climbed over the Rohtang Pass, which was open for only part of the year, snowed in from late autumn to early summer. In 2020 a tunnel of about nine kilometres was opened under the pass, one of the longest highway tunnels in the world at such a height, and named after the former prime minister Atal Bihari Vajpayee. The north portal, where you emerge into Lahaul, is one of the great moments on the road to Ladakh.
The contrast is striking. On the Manali side the valley is wet, green and wooded, with pine and deodar forests and apple orchards. When you come out of the tunnel's north end, you find a drier, harsher world: bare slopes of scree and rock, a few poplar-lined villages, and the Chandra River running through a broad glacial valley. The light is sharper, the sky is bluer, and the air is thinner. The Lahaul valley lies in the rain shadow of the Pir Panjal range, so it gets much less monsoon rain than the south side, which is why it has become a popular route in July and August when the rest of the Himalayas are soaked.
The road beyond the portal is generally good, with long curves and a wide surface, and it follows the river towards Keylong, the district headquarters, some thirty kilometres further on. Traffic can be heavy with trucks and tourist vehicles, and the tunnel itself has speed limits and no overtaking, so be patient. The tunnel is not immune to snow and avalanche, and it can close in bad conditions, so check the latest news.
Simple restaurants at Sissu and Keylong offer dal, rice and tea. The height here is around three thousand metres, and acclimatisation is wise. The best months are June to September, when the roads are open and the air is warm, and the waterfall at Sissu is a reason to stop.