Article Detail Which is Longest road tunnel in the World ? Answer: Lærdal Tunnel (Norway - 24.51 kilometre) Similar Questions : 1. Which is the Densest populated State of India ? Answer: West Bengal 2. Which is largest Dome in India ? Answer: Gol Gumbaz (Karnataka) 3. Which is the longest wall in world ? Answer: Great wall of China 4. Which is the lightest metal ? Answer: Lithium 5. Which is the brightest planet ? Answer: Venus 6. Which is Longest Dam in India ? Answer: Hirakod Dam (Orissa) 7. Which is the shortest day in the year ? Answer: December 22 Read more from - Longest and Largest