1. World’s Longest Tunnel, Switzerland
Leaving behind Japan’s Seikan rail tunnel (54km), recently completed second Gotthard Base Tunnel (approximately 57 km.) in Switzerland in the Swiss Alps has got the title of the longest tunnel in the world. The expenditure goes more than $10 billion and it took 14 years of hard work and technology to complete the tunnel. Due to the tunnel, the distance between Milan and Zurich has lessened considerably and it joins the Europe’s high speed rail network.