, also known as the longest tunnel in the world, is a railway tunnel through the Alps in Switzerland.){kind=link}
Check out the massive engineering and planning undertaken to construct the longest tunnel in the world, also known as the Gotthard Base Tunnel (GBT), a railway tunnel through the Alps in Switzerland.
Source: Largest Dams on YouTube.
Check out the massive engineering and planning undertaken to construct the longest tunnel in the world, also known as the Gotthard Base Tunnel (GBT), a railway tunnel through the Alps in Switzerland.
Source: Largest Dams on YouTube.