Tunnel-8 of the Rishikesh - Karnaprayag Rail Project has officially become India's longest railway tunnel at nearly 14.57 km. Built through the fragile Himalayan terrain in Uttarakhand, the tunnel is a major engineering milestone for the ₹37,000 crore rail project. Once completed, the railway line will significantly improve connectivity, tourism, pilgrimage access in the Garhwal region.