Switzerland’s Underground City: the Gotthard Base Tunnel beneath the Alps

On a damp autumn morning in the Swiss Alps, the mountains can seem to ring… empty. Near Erstfeld, a freight train plunges into the rock, disappears as though the hillside has swallowed it, then turns up again 57 kilometres later on the far side of the country. Up on the pastures, cows graze, unaware that deep beneath their hooves, thousands of tonnes of steel and concrete are alive with unbroken motion. On station platforms, commuters drink coffee, flick through their phones, and board trains that will spend the majority of the trip inside the earth itself.

For close to three decades, Switzerland has steadily drilled, blasted and hewn a concealed world under its peaks.

And this is a city without streets. It runs on tunnels.

Switzerland’s invisible network under the Alps

Once you begin to notice it, it becomes difficult to unsee the sheer scale of Switzerland’s subterranean realm. At the surface, it is all postcard villages, immaculate lakes and neatly groomed slopes. Beneath that image sits a tightly packed mesh of rail tunnels, road tunnels, emergency galleries, ventilation shafts and service caverns-an underground footprint that can rival many mid-sized cities.

A line on a map marked “tunnel” is rarely just a single tube. More often it is a layered structure: twin bores, cross-passages every 325 metres, concealed rooms for maintenance crews, drainage runs, and kilometres upon kilometres of cabling.

The Gotthard Base Tunnel is the most famous chapter in this story. Since opening in 2016, it has run 57.1 kilometres under the Alps, making it the longest railway tunnel in the world. Even so, the word “tunnel” hardly captures it: once you include both tubes and the access links, the system adds up to more than 150 kilometres of galleries.

Construction took 17 years. Crews worked in rotations-often around the clock. Eight workers died. Many thousands more spent ten years or longer travelling not to a normal building site, but straight into the interior of a mountain.

Yet Gotthard was not the beginning. From the 1990s onwards, Switzerland pursued a national programme known as NEAT (New Rail Link through the Alps), designed to change how Europe crosses this barrier of rock and snow. Base tunnels at Lötschberg and Ceneri, major road routes such as the Gotthard Road Tunnel and San Bernardino, plus smaller regional connections, have accumulated layer after layer of underground capacity.

Over time, the country has pushed a substantial share of mobility, logistics-and even parts of its strategic reserves-below ground. Where the Alps once blocked movement, they now carry it. The mountains have become infrastructure.

How do you carve a city into rock?

From above, tunnel building can sound like nothing more than making a hole with an enormous drill. Down below, it is closer to surgery. Long before any blast goes off, geologists “read” the mountain the way a clinician studies a scan. Seismic surveys, core samples and decades of records are used to predict how the rock will behave once it is opened.

Only then do the tunnel boring machines (TBMs) arrive-or the drill-and-blast crews-pushing forward a few metres at a time, day after day, year after year.

In Switzerland, this grind has been refined into a discipline of reliability. On certain sites, the night shift becomes a world of its own. Workers eat raclette in prefabricated canteens and trade jokes in Swiss German, Italian and Portuguese. They go down by lift or by train into the mountain, and may spend full 10-hour shifts without seeing daylight.

When a TBM meets an unexpected pocket of water or a section of unstable rock, the atmosphere changes immediately. The pace drops, engineers crowd around the monitors, and an unspoken reminder returns: the mountain always gets the final say.

So why commit so much money and so many years to these underground arteries? Some of it is straightforward practicality: Switzerland sits at the centre of Europe, and it is largely mountainous, so lorries and trains have to cross somehow. But the stronger driver is political and cultural. In the 1990s, voters supported the Alpine Initiative, effectively insisting that freight should be taken off roads, kept out of valleys, and moved on to rail.

Given the geography, tunnels were the only realistic way to honour that decision. And, frankly, no country commits tens of billions and three decades beneath the ground unless it has collectively decided the trade-off is worth it.

What this underground city changes for everyday life

The benefits become clearest not on a diagram, but in day-to-day travel. The Zurich–Milan journey, once an exhausting haul over winding passes, now slips under the Alps in about three hours. Freight trains that previously laboured up spiral approaches can run on near-flat gradients-quicker, cheaper and with less energy.

The noise and pollution that would otherwise collect in the valleys is pushed out of view, into a realm of concrete linings and ventilation ducts.

For residents of mountain communities, this shift is more than a transport statistic. Fewer heavy vehicles means less winter danger, fewer nights interrupted by engine braking, and less dust in the air. Tourism also finds a new tempo: visitors reach resorts more easily, yet the landscape carries fewer visible scars from surface infrastructure.

There is a muted comfort in knowing that the hardest, dirtiest work of crossing the Alps is happening out of sight-down where the rock is thick and the public rarely goes.

At the same time, this subterranean city reshapes how Switzerland approaches risk and resilience. Many tunnels include parallel safety tubes, frequent cross-passages and evacuation zones that resemble miniature stations tucked into the mountain. Behind the walls sit fire doors, pressure-resistant barriers, backup power rooms and control centres tracking everything from wind speed to train position.

“People see a clean tunnel and think it’s just a hole in the mountain,” a Swiss engineer once told me. “What they don’t see is the hospital-like level of redundancy we hide behind those walls.”

• Multiple tubes: one for each direction, often with a service or safety tube alongside
• Cross passages: escape routes every few hundred metres, like emergency corridors in a shopping centre
• Ventilation caverns: vast hidden chambers that can clear smoke or cool the air
• Monitoring systems: sensors that listen to the rock, the temperature, the vibration
• Access tunnels: narrow galleries only staff and rescue teams ever see

The strange intimacy of a country with its mountains

Switzerland’s relationship with the Alps is almost a paradox. Above ground, the nation markets an ideal of unspoilt nature-walking trails, timber chalets and clean rivers. Below, those same mountains are riddled like a piece of Emmental: rail tubes, road tunnels, military bunkers, emergency shelters and storage depots.

Most people know the feeling: you emerge from a long tunnel into bright daylight and it seems as if you have jumped through time or space. In Switzerland, that sensation is part of the daily routine.

This double existence leads to a quiet question: how much can a landscape be used before its meaning changes? Many Swiss argue that tunnels spare the Alps from surface damage, and there is truth in that-less built above, more done below. Others worry that dependence on invisible mega-projects can distance people from the real scale of what is being carried out in their name.

You don’t feel a 57-kilometre tunnel under your feet the way you feel a motorway slicing through your village.

Still, the underground city also widens the sense of what might come next. Climate pressure is increasing, extreme weather is more common, and surface space is limited. Some planners now talk about putting underground volumes to work for data centres, energy storage, and even protected farming laboratories. Switzerland already has the expertise, the equipment and the consensus-driven political culture that such schemes demand.

The plain fact is this: for three decades the country has not only built tunnels, but also built the capability to live with the mountain from the inside. Whether that becomes a template for others-or a warning-remains a story being written far below the snow.

Key point	Detail	Value for the reader
Scale of underground network	Decades of tunnelling have created a multi-layer system rivaling mid-size cities	Helps you grasp how infrastructure can reshape a landscape without being visible
Gotthard Base Tunnel as emblem	57.1 km rail tunnel, ~150 km of galleries, 17 years of work, billions invested	Offers a concrete example of what it takes to link regions reliably under mountains
Everyday impact	Faster travel, cleaner valleys, complex safety systems hidden in the rock	Shows how large-scale projects quietly influence your trips, air quality, and safety

FAQ:

• How long has Switzerland been building these tunnels? Most of the modern underground network comes from roughly the last 30 years, with major Alpine base tunnels built from the mid-1990s to the 2010s, on top of a century-old tradition of smaller tunnels.
• Is the Gotthard Base Tunnel the only huge tunnel in Switzerland? No, it’s the flagship, but it’s part of a wider system that includes the Lötschberg and Ceneri base tunnels, dozens of long road tunnels, safety galleries, and service caverns.
• How safe is it to travel through these tunnels? Safety standards are extremely strict, with multiple tubes, escape routes, high-tech monitoring, and regular drills involving firefighters, medics, and rail staff.
• Why does Switzerland invest so much underground instead of building more surface roads? The mix of steep terrain, environmental protections, and public votes pushing freight from road to rail makes tunnels the most realistic way to keep mobility flowing without filling valleys with motorways.
• Can other countries copy this underground model? Technically yes, but it demands long-term planning, political consensus, huge budgets, and a culture that accepts multi-decade projects whose biggest parts stay invisible to most citizens.

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