India is set to open what is believed to be the world’s longest high-altitude tunnel, which will reduce the time it takes to travel to the country’s remote disputed border region with China in Ladakh province. The 9km (5.6mi) Atal Rohtang tunnel linking Manali and Leh is located at an altitude of more than 3,000 metres (9,800ft) in the Himalayas, and reportedly would cut several hours off the time it would take to send troops and weapons to the area.