The Eisenerz Tunnel, which connects the cities of Selzthal and Trieben, is Austria's longest railway tunnel. It took six years to construct.
Through the Alps, the Frejus Tunnel connects France with Italy. Its construction took 7 years.
The longest tunnel in China, the Zhongnanshan Tunnel, is situated in the Qinling Mountains. Its construction took five years.
The Laerdal Tunnel, the world's longest vehicular tunnel, links the cities of Laerdal and Aurland. Its building process took five years.
The Sevgi Gonlum Tunnel is the longest tunnel in Turkey and connects the cities of Istanbul and Izmir. It took 9 years to build.
Madrid and Segovia are connected by the Guadarrama Tunnel, which is the longest tunnel in Spain. It took six years to construct.
The Lötschberg Base Tunnel, which links the cities of Frutigen and Raron, is the second-longest tunnel in Switzerland.
The Eurotunnel, sometimes referred to as the Channel Tunnel, is an underwater tunnel that connects France and England. The busiest undersea tunnel in the world was constructed in six years.
The Seikan Tunnel, which connects the Japanese islands of Honshu and Hokkaido, is the longest undersea tunnel in the world. Its construction took 24 years.
The longest and deepest traffic tunnel in the world is the Gotthard Base Tunnel. It cuts travel time in half and connects Switzerland's north and south. The project took 17 years to finish.