In 1480, when Europe was still immersed in the Middle Ages, a group of merchants from northern Italy were faced with something of a dilemma. They needed to bring salt back from Provence, but the only way they could do so was on established mountain routes passed through the heart of Savoy (the ruling family of that region) and, thus, all routes were taxed heavily. Considering these taxes on a load of salt, the merchants knew they were doomed.
So rather than simply paying the tolls and licking their wounds, they did something completely ridiculous. They built a secret passage, a tunnel straight through the Alpine mountains.
Using little more in way of tools than basic medieval metallurgy (pick-axes, hammers, chisels, etc.), a group of workers climbed almost 2900 metres above sea level. Over the course of two years they hammered away at solid stone until they excavated a 75 metre long tunnel directly through the mountain. Can you imagine how difficult it must have been to work at such high altitude, with freezing and sub zero air, without modern health and safety equipment, and using hand tools only?
The Buco di Viso tunnel is significant because it is the first truly human-made tunnel through the Alps. It was not intended for militaristic or royal purposes. It was built to import salt, so the merchants could save money (and a tax burden) for salt shipments they figured out a way to avoid paying.
It's astonishing to know this tunnel still exists more than 500 years later, and that you can experience it today as it was initially intended.
This is a wild and far-out reminder of how far people will go to fight taxes, and protect their income, and in the end, the solutions people arrive at can be as impressive as they are imaginative.
So the next time you grumble about paying taxes, remember these merchants, who literally tunneled through a mountain in order to avoid taxes.