Sonnenberg Tunnel

Sonnenberg Tunnel in Lucerne, Switzerland, is a 1,550 m motorway tunnel that doubles as one of the largest civil defence shelters ever built. For visitors interested in Cold War history, it is among the most unusual sights in the city.

What is the Sonnenberg Tunnel?

The tunnel runs beneath the Sonnenberg hill and carries a section of the motorway around Lucerne. Construction took place between 1971 and 1976. From the start it served two purposes: a road for traffic and a shelter in case of war or disaster. Lucerne voters approved a net credit of about 5.9 million francs for the shelter extension on 1 June 1969.

Why is it called Switzerland's biggest shelter?

When it opened on 26 October 1976, the complex was designed to house roughly 20,000 residents of Lucerne and neighbouring Kriens for about two weeks. In an emergency the tunnel would have been split into districts, rooms and blocks of 64 people each. Inside were planned a three-storey emergency hospital, an operating theatre, a resting ward, a radio studio and a command post. For a time it counted as the largest civilian facility of its kind in the world.

What is left of it today?

Running such a vast installation proved expensive, so the city scaled it back. A review concluded that a public shelter of about 2,000 places was the best option. According to the canton, part of the cavern also serves as a police holding facility during large events. The road tunnel itself remains in service.

Can you visit?

Guided tours under the title "unterirdisch überleben" (surviving underground) have run since 2008 and focus on Cold War nuclear anxiety. The highlights are the operating theatre, the resting ward, the radio studio, the command post and a room called "Life in the Tunnel" with reconstructed bunks and sanitary facilities. Local media have also described a Segway ride through the underground levels. Dates, prices and availability change, so check the City of Lucerne website or the tour operator before you go.

How do you get there?

The tunnel lies in Lucerne at roughly 47.047 N, 8.295 E. You can reach the area from the city centre by public transport or car. The shelter entrance used for tours is separate from the traffic lanes, so you do not walk through the roadway.

Frequently asked questions

How long is the Sonnenberg Tunnel?

It is 1,550 m long and was built between 1971 and 1976.

How many people could the shelter hold?

Originally about 20,000 people from Lucerne and Kriens for around two weeks. Today the public shelter provides about 2,000 places.

Is the tunnel still open to traffic?

Yes, it remains part of the motorway. The visitor area is a separate underground shelter space.

What can you see inside?

The operating theatre, resting ward, radio studio, command post and a recreation of daily life in the shelter.