Switzerland has built an underground world so vast that it competes with cities above

Switzerland is frequently defined by mountains, passes, lakes, and railroads are all part of the image. What lies under the surface is less evident. Over the past several decades, the country has made significant investments in tunnels to transport people, commerce, water, and power across tough terrain. This work has not adhered to a particular plan or era. It has grown gradually, shaped by topography, postwar reconstruction, and demand on transport networks. Today, Switzerland has thousands of tunnels spanning thousands of miles. Some are brief and local. Others run tens of km through solid rock. They constitute a system that supports daily life while remaining largely hidden.

Beneath Switzerland’s mountains lies one of the world’s largest tunnel networks

The scenery offers little variety. Much of the country is mountainous, with dramatic elevation fluctuations over short distances. Building roads and railways on the ground is often slow, expensive, and disruptive. Tunnels offer a way through without being exposed to the elements, steep gradients, or fragile slopes. Mobility is also a major consideration. Switzerland experiences a high level of daily travel, both domestically and internationally. Infrastructure is supposed to be reliable and reach even rural areas. Tunnelling evolved into a practical solution rather than a technical anomaly.

One of the largest tunnel networks in the world

According to the Swiss Tunnelling Society, Switzerland has built around 1,852 tunnels. Together, they stretch for about 2,544 kilometres. These include road tunnels, railway tunnels, and older structures linked to water and power systems. The scale is difficult to picture from the surface. In length alone, the underground network rivals that of major urban transport systems. In some regions, travel underground accounts for a significant share of all movement.

What role do highways play underground

Switzerland’s highway network is among the densest in the world. Around 1,840 kilometres of national highways are currently in operation. About 250 tunnels are part of that network. When planned sections are completed, the total length is expected to reach nearly 1,893 kilometres, with more than 270 tunnels spanning roughly 290 kilometres. Many highways run through tunnels to limit noise, reduce land use, or pass beneath towns. At least three-quarters of the network consists of four-lane divided roads, many of them carrying international traffic.

The tunnel boom began in 1950

According to the Swiss community, the major expansion began after the Second World War. From around 1950, Switzerland started large-scale drainage tunnelling for hydroelectric power. Road tunnel construction followed in the 1980s. Railway tunnels became the main focus from around 2000. Today, more than a tenth of both the motorway and railway networks run underground. This proportion is considered a global record. Around 50 railway tunnels and 55 road tunnels are longer than two kilometres, and their total length continues to increase.

Gotthard Base Tunnel: Longest tunnel in the world

The Gotthard Base Tunnel is often cited as the symbol of this approach. Opened in June 2016, it runs for 57 kilometres, making it the longest tunnel in the world. It allows trains to cross the Alps at low altitude, reducing travel time and energy use. While it stands out, it is part of a broader pattern. Long base tunnels now form the backbone of Swiss rail transport, shifting traffic from roads to rail.

Are tunnels constructed exclusively in the Alps

Much of the current action has taken place away from the elevated alpine regions. Congestion and urbanisation have made the Central Plateau a focal point. A 30-kilometre railway tunnel connecting Zurich and Rupperswil is planned to alleviate a considerable bottleneck. Other developments in Zurich include the Brütener tunnel and a supplementary Zimmerberg tunnel. Road projects also help to construct underground routes, particularly in places like Basel, Lucerne, Bern, and St. Gallen.

What lies beneath Swiss cities

Major cities are building entire tunnel systems around their stations. Zurich opened a new underground station in 2015 to handle east-west traffic. Further underground expansions are planned in Basel, Berne, Geneva and Lucerne. These spaces are functional rather than grand. Platforms, service corridors, ventilation shafts and emergency routes form a quiet layer below the streets. They are designed to cope with daily pressure, then fade back into routine.