Click for Lightbox. Photo: (C) Remko Tanis


This is one hot tunnel. Even in winter, even though it crosses straight through the mighty, snow-capped mountains of the Alps.

On a Tuesday morning in November, at a little before nine, it’s close to 30 degrees Celsius in the St. Gotthardtunnel. That’s 16.9 kilometers of balmy warmth for you while you drive from north of the Alps to south of the Alps. Or the other way around.

Not sure how appealing the idea might be of getting the lounge chairs out to have a chill on the narrow side path, watching 17,000 cars pass you by.

Nonetheless, the idea of 30 degrees is appealing when you drive into it from the foggy coldness of a November morning in central Switzerland.

It’s not even the exhaust from those 17,000 daily cars that causes the Gotthard’s comforting temperature. What does warm up the tunnel, is the massive hot lava core inside of Earth.

The planet’s natural heath is captured, being prevented from getting out by the 1,1 kilometer high massive mountain range that sits on top of the tunnel.

For every one hundred meter you dig into the earth, even counted from the top of a mountain, the temperature rises 3 degrees.

It’s the reason why it’s even warmer in the nearby Gotthard train tunnel, which at 57.1 kilometers is the longest in the world. That thing has more than 2400 meters of mountain sit on top of it, meaning the temperature inside this tunnel goes over 40 degrees Celsius.